In a mixing bowl, combine mashed potatoes, cheese, green onions, garlic powder, salt, and pepper.
Scoop out portions and roll into balls about the size of a golf ball.
Dip each ball into the beaten egg, then roll in breadcrumbs until coated.
Lightly spray the air fryer basket with cooking spray and place the potato balls inside in a single layer.
Air fry at 375°F for 10 to 12 minutes, turning halfway, until golden brown and crispy.
Serve warm with your favorite dipping sauce.