Prep your air fryer: Line the basket or tray with a piece of parchment trimmed to fit. Poke a few holes in the parchment to allow airflow. Preheat the air fryer to 320°F (160°C) for 3–5 minutes.

Cream the butter and sugar: In a large bowl, beat softened butter and granulated sugar until light and fluffy, about 2–3 minutes.

Add wet ingredients: Beat in the egg, lemon zest, lemon juice, and vanilla until smooth. The mixture may look slightly curdled from the citrus—this is normal.

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

Make the dough: Add the dry ingredients to the wet mixture. Mix on low just until no streaks of flour remain. Do not overmix.

Chill briefly (recommended): Cover and chill the dough for 20–30 minutes to make scooping easier and help the cookies keep their shape.

Form the cookies: Scoop 1 1/2-tablespoon portions (a small cookie scoop works well). Roll into balls. If using a coating, roll each ball in granulated sugar or powdered sugar for a crackly finish.

Arrange in the air fryer: Place dough balls on the parchment, leaving about 2 inches between cookies. Gently flatten each ball slightly with your fingers.

Air fry: Cook at 320°F (160°C) for 6–8 minutes until edges look set and the tops are slightly matte. They will firm up as they cool. Avoid over-browning.

Cool: Let cookies rest in the basket for 2 minutes, then transfer to a rack to cool completely.

Optional glaze: Whisk powdered sugar with lemon juice until smooth and drizzle over cooled cookies. Let set for 10–15 minutes.

Repeat: Bake remaining dough in batches. If your air fryer runs hot, reduce time by a minute for later batches.