Turn your air fryer to 375°F and generously grease a donut pan with butter or cooking spray. Set aside.
Pop open your can of biscuits and use a small round cookie cutter (we used ¼ inch one!) to cut out a hole in the center of each biscuit to make a donut shape. You can either air fry the donut holes on a cookie sheet or just throw them away!
Place each biscuit round into your donut pan, gently pressing it into the mold of the pan to shape your biscuits slightly.
Air fryer for 4 minutes and then flip over each donut. Air fry for 4 more minutes on the other side or until golden brown and fully cooked.
Remove the donuts from the air fryer and dip in melted butter first and then cinnamon sugar to fully coat.