In a medium-sized bowl, mix leftover mashed potatoes with crumbled bacon, salt, and pepper. If desired, add 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.

Add flour to a shallow dish. In another dish, scramble egg and 1-2 tablespoons of milk. In a third shallow dish, add breadcrumbs and grated parmesan.

Dip each mashed potato ball in flour, then egg, and then breadcrumbs. Repeat dipping back into the egg and then breadcrumbs again for an extra crispy coating.

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

Cook at 370°F for 4 minutes, shake the basket, spray with additional oil as needed, and continue cooking for 2-3 more minutes until golden brown. Be careful not to overcook as the cheese may ooze out. Serve with ranch dipping sauce.