Preheat the air fryer to 320°F for 3 minutes. Butter two shallow 4-inch pans.
Whisk flour, baking powder, sugar and salt until evenly combined.
Whisk milk, egg, melted butter and vanilla in a second bowl.
Fold wet into dry just until no large flour pockets remain. Small lumps are fine; rest 5 minutes.
Divide about 1/3 cup batter between the pans, keeping batter around 1/2 inch deep. Air fry 6 to 8 minutes.
Turn pancakes out when the top springs back and the center is set. Re-butter pans and repeat with remaining batter.