Peel the potatoes and boil them until fork tender. Drain thoroughly and mash until smooth.
Stir in the minced garlic, parsley, mozzarella, Parmesan, salt, pepper, garlic powder, onion powder, and one egg until fully combined.
Roll the potato mixture into evenly sized balls.
Chill the potato balls for about 20 minutes to help them hold their shape.
Place flour in one bowl, beat the remaining egg in another bowl, and add breadcrumbs to a third bowl.
Coat each potato ball in flour, dip into the beaten egg, then cover completely with breadcrumbs.
Heat vegetable oil to 350°F (175°C).
Fry the potato balls in batches for 3–4 minutes or until golden brown and crispy.
Transfer to a paper towel-lined plate to drain excess oil.
Garnish with fresh parsley and serve immediately with garlic aioli, ranch, marinara, or your favorite dipping sauce.