PREHEAT: Turn the air fryer to 330 degrees and let it run (empty) for 5 minutes while preparing the donuts.
CUT BISCUITS: Open the can of biscuits and using a 1-inch round cutter or biscuit cutter, cut out the center of each one. Set aside the centers for later. Lightly spray the air fryer basket and the biscuits with coconut oil or olive oil spray. (Don't use a nonstick spray--it can affect the coating of your air fryer.)
FRY: Once centers are cut out, add biscuits in one even layer (do not overlap or overcrowd -- we add 4 at a time) in the air fryer basket. Air fry at 350 degrees for 5 minutes.
BUTTER AND CINNAMON-SUGAR: Meanwhile, melt the butter in a microwave-safe bowl in the microwave. Mix the cinnamon and sugar in another separate bowl.
FINISH: Using a pastry brush, brush the air-fried donuts with melted butter. (If you don't have a pastry brush, press the tops of the donuts into the melted butter and shake off excess -- you will need a bit more butter if going this route.) Then dredge the donuts in the cinnamon-sugar mixture by rolling around and spooning sugar over top. Gently shake off the excess cinnamon sugar and enjoy hot.
AIR FRY DONUT HOLES: Take the center of the donuts and air fry for 3 minutes. Dip in butter and then cinnamon sugar; enjoy immediately.
STORAGE: As with most donut recipes, these are best right out of the air fryer while they're hot. They lose flavor and texture after cooling; they also begin to dry out. You can re-warm leftovers in the microwave for 5-10 seconds, but we recommend only making what you will consume and saving leftover (uncooked) biscuit dough in the fridge until ready to make more.
Video
Notes
Note 1: Air fryer: I use, love, and recommend this Air Fryer(affiliate link). Air fryers do vary a bit from brand to brand, so the timing may need to be slightly tweaked for your specific model.Note 2: Butter: If you opt to dip the donuts into the melted butter instead of brushing the tops, you'll likely need a few more tablespoons than what is listed in the recipe.