In a large mixing bowl, use an electric mixer to beat the softened unsalted butter and light brown sugar together for about 3-4 minutes until pale and fluffy.

Add the large egg and pure vanilla extract to the creamed mixture and continue mixing at medium speed for an additional 1-2 minutes.

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

Chop the finely chopped pecans and gently fold them into the cookie dough using a spatula.

Using a cookie scoop, form small balls of the dough and place them onto lined baking sheets. Optionally, press extra pecan halves on top.

Preheat your oven to 350°F (175°C) and bake the cookies for about 10-12 minutes.

Allow the cookies to cool on the baking sheet for about 5 minutes before transferring them to a wire rack to cool completely.