Preheat your air fryer (if it's a model that needs preheating) to 350°F.
Melt your butter in a small bowl or microwave safe measuring cup.
In a medium sized bowl add the melted butter. In a second medium sized bowl combine white sugar, brown sugar and cinnamon. Set aside.
Separate the biscuit dough into individual biscuits and cut out the centers using a biscuit cutter, or an icing tip to create a doughnut shape.
Place the prepared doughnuts in the air fryer basket so they are not touching and have room to expand.
Air fry at 350°F until golden brown, for 4 to 6 minutes. Flip the doughnuts and cook for an additional 2 to 3 minutes.
Remove the doughnuts from the air fryer and place them onto a plate.
Dip each doughnut into the melted butter (making sure to coat top, bottom, and the sides), then dip into the sugar-cinnamon mixture until completely coated.
Serve while warm and enjoy!
Notes
Try different refrigerated biscuits to see what texture you get with the doughnuts.