If there is one flavor combination that reigns supreme in the dessert world, it is undoubtedly peanut butter and chocolate. Now, imagine taking the creamy, nostalgic magic of a classic eclair cake that perfect blend of soft, graham-cracker-turned-cake layers, smooth pudding filling, and glossy chocolate glaze and infusing it with rich, salty-sweet peanut butter. The result? The glorious, easy, and completely irresistible Peanut Butter Chocolate Eclair Cake.
This dessert is a true masterpiece of convenience. Requiring zero oven time, the Peanut Butter Chocolate Eclair Cake comes together in minutes, asking only for patience while it chills in the refrigerator, transforming simple ingredients into a decadent, sliceable dessert. Forget complicated baking projects; this no-bake wonder is perfect for potlucks, holidays, or any time you need a stunning dessert without the stress. We are going to dive deep into exactly how to master the creamy, dreamy layers and the perfect homemade chocolate glaze that make this recipe a guaranteed showstopper.
Why You’ll Absolutely Love This No-Bake Peanut Butter Chocolate Eclair Cake Recipe
In a crowded field of desserts, the Peanut Butter Chocolate Eclair Cake stands out for several compelling reasons. It delivers maximum flavor impact with minimal effort, making it a dream come true for busy home cooks and dedicated dessert enthusiasts alike. If you are skeptical that a no-bake cake made with graham crackers can truly rival a traditional layer cake, prepare to be amazed. The magic lies in the extended chilling time, during which the graham crackers absorb moisture from the rich peanut butter filling, softening completely to create a texture nearly identical to soft, freshly baked cake layers.
Unbeatable Flavor Combination
The synergy between the nutty, savory notes of the peanut butter filling and the deep, slightly bitter sweetness of the homemade chocolate glaze is what elevates this dessert from good to phenomenal. Unlike many store-bought chocolate frostings, the glaze we prepare for this Peanut Butter Chocolate Eclair Cake is cooked on the stovetop, resulting in a thin, intensely glossy, and rich chocolate sheet that cracks delightfully when sliced. This contrast is key: the homemade glaze provides a sophisticated counterpoint to the sweet, fluffy peanut butter filling.
The Simplicity of No-Bake Assembly
One of the biggest advantages of making a Peanut Butter Chocolate Eclair Cake is eliminating the oven entirely. This makes it an ideal choice for summer gatherings when you want to keep the kitchen cool, or when you are juggling multiple dishes for a holiday feast. The assembly process is straightforward: layer, spread, layer, spread, and chill. If you can use a whisk and a spatula, you can master this decadent dessert. It is much easier than tackling a homemade chocolate pudding pie, though we love those too, like our Easy Chocolate Pudding Pie!
A Crowd-Pleasing Nostalgic Treat
The flavor profile of this no-bake cake taps into pure nostalgia. It reminds many people of childhood favorites, combining the creamy texture of pudding and whipped topping with the satisfying crunch (and eventual softness) of graham crackers. Whether you are hosting a formal dinner or a casual backyard BBQ, the Peanut Butter Chocolate Eclair Cake is universally loved. It’s also incredibly easy to slice and serve, holding its shape beautifully once it’s fully chilled, making portion control simple and elegant. Every slice reveals those gorgeous, defined layers of cracker and creamy filling.
Why You Should Try Making This Peanut Butter Chocolate Eclair Cake Today
Beyond the phenomenal taste and the ease of preparation, there are several practical reasons why this specific recipe for Peanut Butter Chocolate Eclair Cake deserves a spot in your rotation. This recipe isn’t just about mixing ingredients; it’s about creating a memorable experience with minimal culinary effort. It addresses common baking frustrations by requiring no proofing, no temperature monitoring, and absolutely no risk of a sunken middle.
Perfect for Make-Ahead Preparation
Because the Peanut Butter Chocolate Eclair Cake absolutely requires extended chilling time (ideally overnight), it is the ultimate make-ahead dessert. You can assemble the entire cake 24 to 48 hours before your event. In fact, the flavor often deepens and the texture improves the longer it sits, allowing the creamy peanut butter filling to fully penetrate the graham crackers. This completely removes the stress of last-minute dessert preparation, allowing you to focus on other parts of your meal.
Customization and Versatility
While the classic components of this Peanut Butter Chocolate Eclair Cake are perfect as written, the structure of the recipe allows for easy customization. You can easily adapt the flavor profiles (more on variations later), making it endlessly versatile. For instance, if you are a huge fan of pure peanut butter flavor, you can sprinkle chopped peanuts between the layers or mix mini peanut butter cups into the filling. If you love how we incorporate peanut butter into classic bakes, check out our recipe for Classic Peanut Butter Cookies they are the perfect accompaniment to this cool cake!
A Budget-Friendly Indulgence
Many show-stopping desserts require expensive, specialized ingredients. The Peanut Butter Chocolate Eclair Cake, however, relies on pantry staples: graham crackers, instant pudding mix, milk, peanut butter, and cocoa powder. This makes it an extremely budget-friendly option that doesn’t sacrifice flavor or presentation. When you bring this towering, layered cake to the table, no one will ever suspect how inexpensive or easy it was to create. It provides a luxurious experience using everyday ingredients, proving that simple components can yield extraordinary results.
The sheer contrast in temperature and texture the cool, light filling against the rich, room-temperature glaze and the soft, cake-like layers is truly addicting. It is a dessert that satisfies the craving for both a creamy pie and a rich chocolate cake, all in one effortless 9×13 dish.
Ingredients and Utensils: Mastering the Peanut Butter Chocolate Eclair Cake Layers
The success of the Peanut Butter Chocolate Eclair Cake lies in using the right ingredients in the right proportions, particularly focusing on the instant pudding and the consistency of the whipped topping. Pay attention to the specific types and temperatures listed below, as they are crucial for achieving the perfect creamy texture.
Ingredients Checklist for the Ultimate Peanut Butter Chocolate Eclair Cake
For the Base and Layers:
- 2 (14.4 oz) boxes of graham crackers: You will need approximately 24 full sheets. We specify boxes rather than sheets because brands vary slightly. Ensure they are fresh and not stale, as they need to absorb moisture effectively. The integrity of the final cake texture relies heavily on the quality and arrangement of these layers.
For the Peanut Butter Filling:
- 2 (3.4 oz) packages instant vanilla pudding mix (or French vanilla): It is absolutely essential that you use instant pudding, not the cook-and-serve variety. The instant mixture sets up quickly with cold milk, providing the necessary stability for the cake structure. French vanilla often provides a slightly richer flavor.
- 3 cups cold whole milk: The temperature of the milk is non-negotiable. Cold milk helps the instant pudding set quickly and properly. Whole milk provides the richest, creamiest filling, essential for a decadent Peanut Butter Chocolate Eclair Cake.
- 1 cup creamy peanut butter: We recommend traditional processed creamy peanut butter (like Jif or Skippy) over natural, oil-separated peanut butter. The stabilizers in the traditional variety ensure the filling sets up firmly and doesn’t separate.
- 1/2 cup powdered sugar (optional, for added sweetness and structure): While the pudding mix is sweet, the addition of powdered sugar helps to slightly stiffen the peanut butter/pudding mixture and provides a smoother, more refined sweetness that balances the saltiness of the peanut butter.
- 1 (8 oz) container frozen whipped topping, thawed (such as Cool Whip): Ensure the whipped topping is completely thawed but still cold. This is the ingredient that provides the airy, light texture to the peanut butter cream. Avoid using homemade whipped cream here unless stabilized, as it tends to weep or deflate more easily than the frozen topping.
For the Chocolate Topping/Glaze:
This glaze is incredibly simple but crucial for that classic eclair finish. It melts into the top layer of the cake slightly, sealing in the moisture.
- 1/2 cup granulated sugar: Provides structure and sweetness to the glaze.
- 1/4 cup unsweetened cocoa powder: Use high-quality cocoa powder for the best depth of flavor. Dutch-processed cocoa powder often yields a darker, smoother chocolate taste, ideal for contrast against the peanut butter.
- 1/4 cup milk (or water): Provides the liquid base. Using milk makes the glaze slightly richer.
- 1/4 cup unsalted butter (4 tablespoons): Adds richness, shine, and the necessary smooth texture to the glaze.
- 1 teaspoon vanilla extract: Added off the heat, this enhances the overall chocolate flavor profile.
Recommended Tools and Utensils for Eclair Cake Success
Having the right tools simplifies the assembly process dramatically, ensuring your Peanut Butter Chocolate Eclair Cake is layered perfectly and efficiently.
- 9×13 Inch Baking Dish: This is the standard size for this recipe. A glass or ceramic dish works best for chilling and serving.
- Large Mixing Bowl (for pudding): Essential for combining the pudding, milk, and peanut butter without splashing.
- Whisk: Necessary for thoroughly mixing the instant pudding. Electric mixers can also be used on low speed, but a good old-fashioned whisk ensures everything dissolves properly.
- Small Saucepan: Needed specifically for preparing the chocolate glaze.
- Rubber Spatula or Spoon: Crucial for gently folding the whipped topping into the peanut butter mixture. A flexible spatula is also ideal for spreading the layers evenly without disturbing the graham crackers underneath.
- Measuring Cups and Spoons: Accuracy is important, especially when measuring the liquid for the pudding.
- Plastic Wrap: You will need this to cover the cake tightly during its long chilling period, preventing the surface from drying out and picking up refrigerator odors.
By gathering these ingredients and tools, you are setting yourself up for success. Remember, preparation is key ensure your whipped topping is thawed and your milk is cold before starting the filling, guaranteeing a smooth and thick peanut butter cream for your exquisite Peanut Butter Chocolate Eclair Cake.
Detailed Instructions: How to Assemble Your Peanut Butter Chocolate Eclair Cake
This recipe is broken down into simple phases: preparation, making the filling, assembly, and chilling. Follow these steps precisely to ensure your no-bake cake sets up beautifully with a light, airy filling and a striking chocolate top.
Step 1: Prepare the Baking Dish and Cracker Base
- Select the Dish: Take your 9×13 inch baking dish.
- Lay the Foundation: Lay a single, even layer of graham crackers across the bottom of the dish. This requires fitting the crackers like puzzle pieces. You will inevitably need to break pieces as necessary to fill gaps completely. The goal is to cover the base entirely to create a sturdy foundation for the rich peanut butter filling. Set this prepared base aside.
Step 2: Prepare the Peanut Butter Pudding Base
- Activate the Pudding: In a large mixing bowl, whisk together the instant vanilla pudding mix and the 3 cups of cold whole milk. Continue whisking vigorously for approximately 2 minutes until the mixture begins to thicken significantly. Do not over-whisk past the 2-minute mark, but ensure no dry powder remains.
- Soften the Peanut Butter: In a separate small bowl, microwave the 1 cup of creamy peanut butter briefly (about 30 seconds to 1 minute, depending on your microwave power) until it is slightly softened and easily stirrable. This softening step is essential, as it prevents the peanut butter from clumping when added to the cold pudding mixture.
- Combine the Flavors: Add the softened peanut butter and the optional powdered sugar into the thickened pudding mixture. Stir well until the pudding is completely uniform and streak-free. The mixture should be thick, creamy, and boast a perfect peanut butter hue.
Step 3: Fold in the Whipped Topping
This is where the filling gets its signature lightness.
- The Gentle Fold: Gently fold the thawed whipped topping into the peanut butter pudding mixture using a large rubber spatula. Use a cutting motion, bringing the mixture from the bottom up and over.
- Do Not Deflate: Be careful not to deflate the whipped topping. Overmixing will make the filling runny, resulting in a soggy rather than cake-like Peanut Butter Chocolate Eclair Cake. Fold just until no white streaks of whipped topping remain.
Step 4: Assemble the Eclair Cake Layers
Now we build the classic layered structure.
- First Filling Layer: Spread exactly half of the peanut butter filling evenly over the graham cracker base layer in the prepared baking dish. Spread gently to avoid shifting the crackers.
- Second Cracker Layer: Add a second, complete layer of graham crackers directly on top of the filling. Again, ensure the crackers fit snugly and cover the filling entirely.
- Final Filling Layer: Spread the remaining half of the peanut butter filling evenly over the second graham cracker layer.
- Top Cracker Layer: Place one final, complete layer of graham crackers on top of the final layer of filling. This top layer will receive the chocolate glaze.
- Temporary Chill: Cover the dish lightly with plastic wrap and place it in the refrigerator while you prepare the glaze.
Step 5: Prepare the Chocolate Glaze
This quick stovetop glaze is intensely chocolatey and provides the perfect finish for the Peanut Butter Chocolate Eclair Cake.
- Combine Dry and Wet: In a small saucepan, combine the granulated sugar, cocoa powder, milk, and butter.
- Cook the Glaze: Heat the mixture over medium heat, stirring continuously, until the butter is completely melted and the sugar is fully dissolved. Bring the mixture to a gentle boil and allow it to cook for exactly 1 minute, stirring occasionally to prevent scorching.
- Finish the Glaze: Remove the pan from the heat immediately. Stir in the vanilla extract.
Step 6: Glaze and Chill the Cake
Patience is the secret ingredient that transforms this into a true eclair cake.
- Cool Slightly: Allow the chocolate glaze to cool slightly (about 5 to 10 minutes) before pouring it. Practical Tip: If the glaze is too hot, it will melt the whipped topping below the top cracker layer, resulting in a messy, runny cake. It should be warm enough to pour easily but not steaming.
- The Final Topping: Pour the slightly cooled chocolate glaze evenly over the top layer of graham crackers. Use a spatula to spread gently if needed, ensuring the entire surface is covered in a glossy, uniform layer.
- The Critical Chill: Cover the dish tightly with plastic wrap. Ensure the plastic wrap doesn’t touch the glaze if possible (you can use toothpicks to tent the wrap). Refrigerate the Peanut Butter Chocolate Eclair Cake for a minimum of 8 hours, or preferably overnight. The extended chilling time is absolutely necessary for the graham crackers to fully soften and achieve the classic, tender eclair cake texture.
Step 7: Serve
Once fully set, the Peanut Butter Chocolate Eclair Cake is ready.
- Slice and serve the chilled dessert. Use a large, sharp knife for clean cuts.
- Store any leftovers covered tightly in the refrigerator for up to 4 days.
Tips, Variations, and Troubleshooting for Your Peanut Butter Chocolate Eclair Cake
While the recipe for this magnificent no-bake dessert is relatively simple, there are common pitfalls and many ways to customize the flavor. Use these tips to ensure a flawless cake every time.
Common Mistakes to Avoid
The success of the Peanut Butter Chocolate Eclair Cake hinges on two factors: the consistency of the filling and the duration of the chill.
- Not Chilling Long Enough: If you slice the cake before 8 hours, the graham crackers will still be firm and crunchy. This defeats the purpose of the eclair cake structure. Always chill overnight for the best result.
- Using Hot Glaze: Pouring steaming hot glaze directly onto the top cracker layer will instantly melt the creamy peanut butter filling just beneath the surface, causing the layers to collapse. Ensure the glaze is cool enough to touch before pouring.
- Substituting Instant Pudding: Cook-and-serve pudding requires heat activation and has a different setting mechanism. It will not work for this recipe and will result in a runny filling. Stick to instant pudding.
- Over-Folding the Whipped Topping: Folding too aggressively will knock the air out of the whipped topping, resulting in a dense, heavy filling rather than the signature light, airy cream.
Delicious Variations for Your Eclair Cake
Feel free to experiment with these ideas to create your own signature Peanut Butter Chocolate Eclair Cake:
- Gluten-Free Peanut Butter Chocolate Eclair Cake: Easily accomplished by substituting regular graham crackers with gluten-free graham crackers. The chilling time remains the same.
- White Chocolate Drizzle: Once the dark chocolate glaze is set, melt 1/4 cup of white chocolate chips with 1 teaspoon of coconut oil and drizzle it decoratively over the top for an added layer of complexity and visual appeal.
- Extra Crunch: Sprinkle chopped roasted peanuts or miniature peanut butter cups over the top of the cake right after the glaze has been applied, or fold them gently into the filling.
- Nutella Swirl: Substitute half the creamy peanut butter with Nutella for a rich, hazelnut-chocolate flavor profile. Ensure the Nutella is slightly warmed before mixing it into the pudding base.
- Dairy-Free Option: Use a non-dairy instant pudding mix (ensure it sets with non-dairy milk like almond or soy), use a quality dairy-free butter substitute for the glaze, and swap the Cool Whip for a non-dairy whipped topping substitute.
For more baking inspiration and dessert twists, be sure to follow my latest creations and recipe pins on Pinterest!
Experimenting with fillings is part of the fun of a no-bake cake. If you enjoy quick, easy desserts, consider checking out our recipe for No-Bake Peanut Butter Pie, which shares that delicious, creamy texture but in a pie crust format.
Nutritional Information and Indulgence: The Peanut Butter Chocolate Eclair Cake
The Peanut Butter Chocolate Eclair Cake is a delightful indulgence, and like most decadent desserts, it should be enjoyed in moderation. Providing exact nutritional values for homemade recipes can be complex due to variations in specific brands and serving sizes. However, we can break down the typical components to understand what each delicious slice provides.
Estimated Nutritional Breakdown (Per 1/12th Serving)
Assuming a 9×13 cake is cut into 12 generous portions, here is a generalized estimate based on standard pantry ingredients:
- Calories: Approximately 380 – 450 calories per serving. This range accounts for the rich butter in the glaze and the whole milk/whipped topping in the filling.
- Total Fat: Approximately 20g – 25g. The majority of the fat comes from the creamy peanut butter and the butter used in the chocolate glaze.
- Saturated Fat: Approximately 8g – 12g.
- Carbohydrates: Approximately 45g – 55g. This includes complex carbohydrates from the graham crackers and sugars from the glaze and instant pudding mix.
- Protein: Approximately 8g – 12g. Peanut butter is an excellent source of plant-based protein, which significantly boosts the protein content compared to a standard vanilla eclair cake.
- Sugar: Approximately 30g – 40g (naturally occurring and added).
The Benefits of Indulging in a Slice
While this is a treat, certain components offer positive aspects:
- Protein Power from Peanut Butter: Peanut butter provides healthy fats and a significant amount of protein, which contributes to satiety and sustained energy. The protein in the filling makes this dessert slightly more substantial than a typical light, creamy dessert.
- Calcium Content: The use of whole milk and pudding mix ensures each serving contributes a good amount of calcium, essential for bone health.
- Antioxidants in Cocoa: Real unsweetened cocoa powder, used generously in the glaze, is rich in antioxidants and flavonoids, which have been linked to heart health benefits when consumed as part of a balanced diet.
- The Joy Factor: Perhaps the most significant “benefit” of enjoying a slice of homemade Peanut Butter Chocolate Eclair Cake is the sheer pleasure it brings. Cooking and sharing beloved comfort foods is excellent for mental well-being and connection.
If you are looking to slightly reduce the calories or fat content, you can opt for 2% milk and a light whipped topping substitute, though be aware that these substitutions may slightly affect the final richness and setting texture of the Peanut Butter Chocolate Eclair Cake. Enjoy this decadent dessert fully, knowing exactly how easy and satisfying it was to create.
FAQs About Peanut Butter Chocolate Eclair Cake
We’ve compiled answers to the most common questions about making, serving, and storing this easy no-bake masterpiece, ensuring your Peanut Butter Chocolate Eclair Cake turns out perfectly every time.
How long does the Peanut Butter Chocolate Eclair Cake need to chill?
The cake requires a minimum of 8 hours of chilling time, but chilling it overnight (12 to 24 hours) yields the best results. This extended time is critical for allowing the graham crackers to fully soften and absorb the moisture from the peanut butter filling, achieving the desirable tender, cake-like texture.
Can I freeze this Peanut Butter Chocolate Eclair Cake?
While it’s possible to freeze this cake, freezing and thawing may slightly change the texture of the filling, sometimes causing it to weep slightly. If you choose to freeze, wrap the fully chilled cake tightly in plastic wrap and then foil. Thaw it slowly overnight in the refrigerator before serving, preferably within two months of freezing.
What happens if my chocolate glaze is too thick?
If your chocolate glaze is too thick after cooling slightly, you can thin it out by stirring in a teaspoon of warm milk or water at a time until you reach a pourable consistency. Ensure you stir thoroughly to maintain its smooth, glossy texture before pouring it over the Peanut Butter Chocolate Eclair Cake.
Can I use crunchy peanut butter instead of creamy peanut butter?
Yes, you can certainly use crunchy peanut butter, but be aware that the filling will no longer be uniformly creamy. The pieces of peanuts will add a fantastic crunchy texture that contrasts beautifully with the soft layers, making for an even more satisfying Peanut Butter Chocolate Eclair Cake experience.
Why do I need to warm the peanut butter before adding it to the pudding?
Peanut butter is thick and dense when cold or at room temperature. If you add it directly to the cold pudding mix, it will clump and be difficult to incorporate smoothly. Warming it slightly (softening it) ensures it blends perfectly into the pudding and whipped topping mixture, resulting in a perfectly smooth, streak-free filling for your Peanut Butter Chocolate Eclair Cake.
Conclusion: Your New Favorite No-Bake Dessert
The Peanut Butter Chocolate Eclair Cake is more than just a dessert; it’s an experience. It offers all the rich, layered sophistication of a classic baked cake, but with the unparalleled ease and convenience of a no-bake recipe. We have successfully combined the light, airy texture of a traditional eclair cake with the universally adored pairing of smooth peanut butter and deep, decadent chocolate.
From the moment you start whisking the instant pudding to the satisfying slice through the perfectly soft, cake-like layers after an overnight chill, this recipe is pure joy. It is perfect for those times when you need an impressive, crowd-pleasing dessert that requires minimal active cooking time. Remember the key rules: use cold milk for the pudding, soften that peanut butter, fold the whipped topping gently, and above all, do not rush the chilling time!
We encourage you to try this recipe for the Peanut Butter Chocolate Eclair Cake for your next family gathering or party. It’s guaranteed to disappear quickly, earning you rave reviews and requests for the recipe. Share your creations, let us know what variations you tried, and leave a comment below once you’ve experienced the magic of this effortless dessert!

Peanut Butter Chocolate Eclair Cake (No-Bake)
Equipment
- 9x13 inch Baking Dish
- Large Mixing Bowl
- Saucepan
- Whisk and Spatula
Ingredients
For the Base and Layers
- 2 boxes graham crackers (14.4 oz each, approximately 24 full sheets)
For the Peanut Butter Filling
- 2 packages instant vanilla pudding mix (3.4 oz packages, or French vanilla)
- 3 cups cold whole milk
- 1 cup creamy peanut butter
- 1/2 cup powdered sugar (Optional, for added sweetness and structure)
- 1 container frozen whipped topping (8 oz, thawed, such as Cool Whip)
For the Chocolate Topping/Glaze
- 1/2 cup granulated sugar
- 1/4 cup unsweetened cocoa powder
- 1/4 cup milk (or water)
- 1/4 cup unsalted butter (4 tablespoons)
- 1 teaspoon vanilla extract
Instructions
Prepare the Dish and Filling
- Prepare the Baking Dish: Select a 9x13 inch baking dish. Lay a single, even layer of graham crackers across the bottom of the dish, breaking pieces as necessary to fill gaps completely. Set aside.
- Prepare the Peanut Butter Pudding Base: In a large mixing bowl, whisk together the instant vanilla pudding mix and the cold milk for approximately 2 minutes until the mixture begins to thicken. Briefly microwave the peanut butter (about 30 seconds) until it is slightly softened and stirrable. Add the softened peanut butter and the optional powdered sugar into the thickened pudding mixture. Stir well until the pudding is completely uniform and streak-free.
- Fold in the Whipped Topping: Gently fold the thawed whipped topping into the peanut butter pudding mixture using a spatula. Be careful not to deflate the whipped topping; fold just until no white streaks remain. This creates the light, airy filling.
Assembly
- Assemble the First Layer: Spread half of the peanut butter filling evenly over the graham cracker base layer in the prepared baking dish. Add a second, complete layer of graham crackers directly on top of the filling.
- Complete the Assembly: Spread the remaining half of the peanut butter filling evenly over the second graham cracker layer. Place one final, complete layer of graham crackers on top of the final layer of filling. Cover the dish lightly with plastic wrap and place it in the refrigerator while you prepare the glaze.
Glaze and Chill
- Prepare the Chocolate Glaze: In a small saucepan, combine the granulated sugar, cocoa powder, milk, and butter. Heat the mixture over medium heat, stirring continuously, until the butter is completely melted and the sugar is dissolved. Bring the mixture to a gentle boil and allow it to cook for 1 minute, stirring occasionally. Remove the pan from the heat and stir in the vanilla extract.
- Glaze the Cake: Allow the chocolate glaze to cool slightly (about 5 to 10 minutes) before pouring it. Pour the slightly cooled chocolate glaze evenly over the top layer of graham crackers, spreading gently with a spatula if needed to ensure the entire surface is covered.
- Chill and Serve: Cover the dish tightly with plastic wrap and refrigerate the cake for a minimum of 8 hours, or preferably overnight. The extended chilling time is necessary for the graham crackers to soften and achieve the classic eclair cake texture. Slice and serve chilled.