Preheat the oven to 350℉.
- Fit a hand mixer with the beater attachment. Then, in a large mixing bowl, beat the peanut butter, brown sugar, and granulated sugar until smooth and fluffy. Add the egg and vanilla and continue to mix until everything is incorporated.
- Scoop up the dough into heaping tablespoons and use your hands to roll into balls. Place the cookie dough balls on a baking sheet, about 2 inches apart.
- Use a fork to gently press a crisscross pattern into each cookie. This will help to bake evenly.
- Bake at 350℉ for 6-8 minutes, until they begin spreading and become aromatic. Don’t wait for them to brown.
Cool before serving.