Preheat the oven to 350°F (175°C). Line two baking sheets with parchment paper or silicone mats.
In a large mixing bowl, beat the butter, granulated sugar, and brown sugar together until light and fluffy, about 2 minutes.
Add peanut butter, egg, and vanilla. Mix until smooth and creamy. Scrape down the sides of the bowl to make sure everything is well combined.
In a separate bowl, whisk together the flour, baking soda, baking powder, and salt. Slowly add this mixture to the wet ingredients, mixing just until the dough comes together. Don’t overmix, it should be soft but not sticky.
Scoop about 1 tablespoon of dough per cookie and roll it into balls. Place them 2 inches apart on the prepared baking sheets.
Use a fork dipped in sugar to press a crisscross pattern on top of each cookie.
Bake for 9–11 minutes, just until the edges start to turn golden. The centers may look slightly underbaked, that’s perfect. They’ll continue to set as they cool.
Let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack.