Cut each biscuit into four equal pieces, they will look like small triangles.
Place each donut hole into your air fryer basket and air fry at 350 degrees F for 8 minutes total, shaking halfway through at the 4 minute mark.
While the donuts are cooking, pour the cinnamon and sugar into a gallon size freezer bag and set aside.
Now melt 1 stick of butter in a large mixing bowl.
Remove the air fried donut holes from the basket, place them into the bowl of melted butter and toss to fully coat.
Transfer the coated donut holes to the cinnamon sugar mixture and shake until all sides of each donut hole are covered.
If you want to make an icing, just whisk together powdered sugar, milk and vanilla until you get your desired consistency and drizzle on top or serve alongside the donut holes in a small bowl for dipping.