Add the mashed potatoes to a bowl with the cornstarch, and mix until a dough is formed. The dough should be almost like a thick gnocchi dough, and should hold its shape easily. You can add more cornstarch or flour as needed.
Using clean hands, roll into balls, slightly smaller than a golf ball.
Transfer to an air fryer. Spray liberally with oil. Air fry at 450F for 15 to 20 minutes, until the outsides are golden brown.
Enjoy immediately.
