In a medium-sized bowl, mix leftover mashed potatoes with crumbled bacon, salt, black pepper, and if desired, garlic powder.

With floured hands, scoop mashed potato into the palm of your hand. Flatten into a disk and add a cube of cheese to the center. Carefully form into a ball, ensuring the cheese is completely covered with potatoes.

Prepare three shallow dishes: add flour to one, scrambled eggs mixed with 1-2 tablespoons of milk to another, and breadcrumbs mixed with grated parmesan to the last dish. Dip each potato ball in flour, then in egg, and then breadcrumbs. Repeat the egg and breadcrumb dipping for an extra crispy coating.

Add a single layer of mashed potato balls to the air fryer basket. Lightly spray them with cooking oil.

Cook at 370°F for 4 minutes. Shake the basket, spray with additional oil as needed, and continue baking for 2-3 more minutes until golden brown.