Tear off about ⅓ of the garlic bread, break it into pieces and add it to a food processor. Process into crumbs. You'll need 1⅓ cups of garlic bread breadcrumbs (or maybe a little bit more) for the meatballs. Set it aside. You can use the rest of the loaf of garlic bread to broil garlic bread to go with your meal.
PREPARE THE MEATBALLS:
Preheat the oven to 350℉. Line a large, rimmed baking sheet with parchment paper.
In a large bowl, combine the ground meats, breadcrumbs, eggs, Parmesan, parsley, salt a couple of grinds of pepper and a splash of cream. Mix together well with clean hands. If the mixture is too wet, incorporate more garlic bread crumbs. Roll into 32 1½-inch balls and place on a rimmed baking sheet. Place the baking sheet with the meatballs into the freezer for 5 to 10 minutes to firm them up a bit.
Bake for 30 minutes, until cooked through and lightly browned. Add marinara sauce to a large pan, add the meatballs to the sauce, and simmer until warmed. Then your meatballs in the sauce are ready to eat!