Preheat the oven to 400?F. Line a baking sheet with foil and spray with non-stick spray.

Combine ground beef, egg, breadcrumbs, parmesan cheese, salt, minced garlic, chopped onion, black pepper, and parsley (if desired) in a bowl. Stir just until combined, do not over mix. Add a tablespoon or two of water as needed to keep a wet mixture.

Cut cheese into 24 cubes about 1/2" in size. Use a medium cookie scoop or spoon to scoop the meat. Place a piece of cheese in the center and wrap the meat around the cheese. Form into 1 1/2" balls and place on the pan.

Bake uncovered for 17-20 minutes, or until no longer pink in the middle. Turn halfway through, so the bottoms don't brown.

Allow meatballs to rest for 5 minutes before serving. Serve with lettuce, tomatoes, pickles, and hamburger sauce.