Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a medium bowl, whisk together the flour and baking powder until well combined.

In a stand mixer or large bowl, cream the softened butter with the brown sugar and granulated sugar until pale and fluffy.

Add the peanut butter and mix until smooth. Beat in the egg and vanilla extract, scraping down the sides as needed.

Gradually mix in the dry ingredients until just incorporated. Do not overmix.

Roll the dough into 1-inch balls and place on the prepared baking sheet, spacing them out evenly.

Using a fork dipped in sugar, press down each ball gently in a crisscross pattern.

Bake for 8 to 10 minutes or until the edges start to turn golden. Let the cookies rest on the baking sheet before transferring to a wire rack to cool completely.