Cream the softened unsalted butter and light brown sugar in a large mixing bowl using an electric mixer on medium speed for about 3-4 minutes until pale and fluffy.

Add one large egg and a teaspoon of pure vanilla extract into the creamed mixture. Mix on low speed until smooth and homogenous, about 1-2 minutes.

In a separate bowl, whisk together all-purpose flour and baking powder. Gradually add this dry mixture to the wet ingredients, mixing on low speed just until combined.

Gently fold in the finely chopped pecans into the cookie dough with a spatula, ensuring even distribution throughout.

Using a cookie scoop or rounded tablespoon, portion the dough onto a parchment-lined baking sheet and press extra pecan pieces on top.

Preheat oven to 350°F (175°C). Bake cookies for 10-12 minutes until edges are golden brown and centers remain slightly soft.

Remove cookies from the oven and let them cool on the baking sheets for about 5 minutes before transferring to a wire rack.