Preheat the oven: Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
Mix the wet ingredients: In a large bowl, beat together the peanut butter, softened butter, granulated sugar, and brown sugar until creamy. Add in the egg and vanilla extract, mixing until fully combined.
Combine the dry ingredients: In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.
Make the dough: Gradually add the dry ingredients to the wet mixture, stirring until a dough forms.
Shape the cookies: Roll the dough into 1-inch balls and place them on the prepared baking sheet. Press the dough balls down gently with a fork to create a crisscross pattern.
Bake: Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden. Be careful not to overbake.
Cool: Let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.