Preheat oven to 450 degrees F. Cover a 12-inch, oven proof skillet (such as cast iron), or a rimmed cookie sheet with foil and set aside.
Gently mix together meat, 1/4 cup Parmesan, 1/4 cup spaghetti sauce, Panko, garlic and Italian seasoning. Add a pinch of salt and pepper.
Form meat mixture into even-sized balls (I like to use an ice cream scoop). Place in the foil covered skillet or sheet pan close together but not touching. Bake for 12-14 minutes.
Remove skillet from the oven. Carefully lift a corner of the foil with tongs to keep the dripping in the foil and transfer meatballs from the foil to the pan. If using a sheet pan, simply transfer to the skillet.
Pour 1-2 cups spaghetti sauce over and around the meatball, depending on how saucey you want them to be. Sprinkle Parmesan cheese evenly over the meatballs, then Mozzarella, then parsley.
Bake for an additional 10-12 minutes or until sauce is hot and cheese is completely melted.
Serve hot with pasta or breadsticks, or on french rolls, with a big green salad on the side.