Start by preparing the biscuit dough for the air fryer. Use a biscuit cutter and cut out the middle. You can use these later to make mini donuts. Spray your air fryer basket with non-stick cooking spray. Place your biscuit dough (I needed to do it in 2 batches, as you don't want them crowded) Set the temperature to 350 degrees F, for 5 minutes. After 5 minutes, remove the biscuits, place on a cutting board and place the second batch in the air fryer basket Meanwhile in a small mixing bowl, mix together the powdered sugar, unsweetened baking cocoa, butter (melted), vanilla and milk. Mix well, until everything is well blended. Wait a few minutes, until the donuts are cooled, and then spread the chocolate frosting on the donuts. Plate, serve and enjoy!