Preheat your oven to 350°F (175°C) and line two large baking sheets with parchment paper or silicone baking mats.

In a large mixing bowl, cream together the softened butter, granulated sugar, and light brown sugar until light and fluffy using an electric mixer.

Beat in the eggs one at a time, mixing well after each addition, then stir in the vanilla extract, scraping down the bowl as needed.

In a separate medium bowl, whisk together the all-purpose flour, baking soda, and salt.

Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined, being careful not to overmix.

Use a large cookie scoop (about ¼ cup) to portion the dough onto the prepared baking sheets, spacing them 2-3 inches apart.

Gently press the center of each cookie dough ball with the back of a spoon or your thumb to create a shallow indentation for the filling.

Bake the cookie bases for 8-10 minutes until the edges are set but the centers are still pale and soft, then remove from the oven.

While the cookies bake, prepare the filling by whisking together melted butter, granulated sugar, dark corn syrup, egg, vanilla extract, and a pinch of salt until smooth, then stir in the chopped pecans.

Spoon 1-2 tablespoons of the pecan pie filling into each partially baked cookie indentation and return to the oven for another 10-15 minutes.

Continue baking until the cookie bases are golden brown and the pecan pie filling is set and slightly caramelized. The center of the filling should no longer be liquid.

Cool the cookies on the baking sheets for at least 15-20 minutes before transferring them to a wire rack to cool completely, as the filling will be very hot and delicate.