01 - Preheat oven to 350°F (175°C). Line two baking sheets with parchment paper.
02 - In a large bowl, beat together butter, granulated sugar, and brown sugar until light and fluffy.
03 - Add peanut butter, egg, and vanilla extract. Beat until well combined.
04 - In a separate bowl, whisk together flour, baking powder, baking soda, and salt.
05 - Gradually add dry ingredients to the wet ingredients, mixing until just combined.
06 - Scoop tablespoon-sized portions of dough and roll into balls. Place on the prepared baking sheets about 2 inches apart.
07 - Flatten each ball slightly with a fork, creating a crisscross pattern.
08 - Bake for 8–10 minutes, until the edges are lightly golden. (Cookies will continue to set as they cool.)
09 - Let cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.