Cream the fats and sugars: In a medium bowl, beat the softened butter, peanut butter, granulated sugar, and brown sugar until smooth and fluffy, about 1–2 minutes. This step helps the cookies hold their shape and get light.

Add egg and vanilla: Mix in the egg and vanilla until fully combined. Scrape the bowl so everything blends evenly.

Combine the dry ingredients: In a separate small bowl, whisk flour, baking soda, baking powder, and salt.

Bring it together: Add the dry ingredients to the wet mixture. Stir until just combined. If using add-ins like chocolate chips or chopped peanuts, fold them in now. The dough should be soft but not sticky.

Chill briefly (optional but helpful): If the dough feels very soft, chill it for 15 minutes. This makes shaping easier and helps maintain that classic crisscross pattern.

Prep the air fryer: Line the air fryer basket with a piece of parchment cut to fit, leaving space around the edges for air flow. Lightly mist with cooking spray if your basket is prone to sticking.

Shape the cookies: Scoop tablespoon-sized balls (about 1 to 1.5 tablespoons each). Roll in granulated sugar for a light crust. Place balls in the basket, spaced about 1.5 inches apart. Use a fork to press a crisscross pattern, flattening to about 1/2-inch thick.

Air fry: Cook at 320°F (160°C) for 6–8 minutes. Start checking at 6 minutes. The edges should look set and lightly golden; centers will look soft. Do not overbake—they firm up as they cool.

Cool: Let cookies rest in the basket for 3 minutes to set, then transfer to a rack to cool completely. If desired, add a tiny pinch of flaky salt on each while warm.

Repeat: Bake remaining dough in batches. If your kitchen is warm, keep the dough in the fridge between batches for best shape.