by GRACE ELKUS
Line a baking sheet with parchment paper. Combine sugar and cinnamon in a shallow bowl; set aside.
Remove the biscuits from the can, separate them, and place them on the baking sheet. Use a 1-inch round biscuit cutter (or similarly-sized bottle cap) to cut holes out of the center of each biscuit.
Lightly coat an air fryer basket with olive or coconut oil spray (do not use nonstick cooking spray such as Pam, which can damage the coating on the basket).
Place 3 to 4 donuts in a single layer in the air fryer (they should not be touching). Close the air fryer and set to 350°F. Cook, flipping halfway through, until the donuts are golden-brown, 5 to 6 minutes total.
Transfer donuts to the baking sheet. Repeat with the remaining biscuits. You can also cook the donut holes — they will take about 3 minutes total.
Brush both sides of the warm donuts with melted butter, place in the cinnamon sugar, and flip to coat both sides. Serve warm.