In a medium saucepan over medium heat, combine granulated sugar and water. Do not stir. Cook, swirling the pan occasionally, until the sugar dissolves and turns a deep amber color (about 8-10 minutes). Be careful not to burn it.

Carefully pour in the corn syrup (it will bubble up). Stir to combine.

Remove from heat and carefully whisk in the butter, a piece at a time, until melted and smooth.

Stir in the pecan halves.

Pour the caramel mixture onto a parchment-lined baking sheet and spread it out thinly to cool completely. Once cooled, break it into small pieces.

Preheat oven to 350°F (175°C). Line baking sheets with parchment paper.

In a large bowl, cream together the softened butter, granulated sugar, and brown sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla.

In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix. Stir in the chopped pecans.

Drop rounded tablespoons of cookie dough onto the prepared baking sheets, leaving about 2 inches between each cookie. Press a few pieces of the cooled caramelized pecan mixture into the center of each cookie.

Bake for 10-12 minutes, or until the edges are golden brown. Let the cookies cool on the baking sheets for a few minutes before transferring them to a wire rack to cool completely.