Preheat Oven: Set your oven to 350°F (175°C). Line a baking sheet with parchment paper or a non-stick baking mat.
Mix Dry Ingredients: In a medium bowl, whisk together flour, baking powder, baking soda, and salt.
Cream Butter And Sugars: In a large bowl, cream the butter, granulated sugar, and brown sugar until light and fluffy.
Add Egg And Vanilla: Beat the egg and vanilla extract until well combined.
Combine Wet And Dry Ingredients: Gradually mix the dry ingredients into the wet ingredients until combined. Avoid over-mixing.
Optional Add-Ins: Fold in chocolate chips or chopped pecans if using.
Shape Cookies: Drop spoonfuls of dough onto the prepared baking sheet, spacing them about 2 inches apart.
Bake: Bake for 10-12 minutes or until the edges are lightly golden.
Cool: Allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.