1. Preparing the Cookie Dough

1. Cream together butter, granulated sugar, and brown sugar until smooth and fluffy.
2. Add the egg and vanilla extract, beating until well combined.
3. In a separate bowl, whisk together the flour, baking powder, and salt. Gradually add the dry ingredients to the wet ingredients, mixing until just incorporated.
4. Chill the dough in the refrigerator for at least 30 minutes to firm up.

2. Making the Pecan Filling

1. In a mixing bowl, combine chopped toasted pecans, corn syrup, brown sugar, melted butter, and vanilla extract. Stir until the mixture is well-coated and evenly combined. Set aside.

3. Assembling the Cookies

1. Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.
2. Scoop small balls of dough (about 1 tablespoon each) and place them on the prepared baking sheet.
3. Flatten each dough ball slightly and create a small indentation in the center. Spoon about 1 teaspoon of the pecan filling into the center of each cookie.
4. Fold the edges of the dough over the filling to seal, then reshape into a ball.

4. Baking the Cookies

1. Bake the cookies for 10–12 minutes, or until golden brown around the edges and slightly firm in the center.
2. Let the cookies cool on the baking sheet for a few minutes before transferring to a wire rack to cool completely.