Mince two cloves of garlic.
In a large bowl, combine ground beef, bread crumbs, egg, parsley, minced garlic and ¼ cup Parmesan. Season with salt and pepper. Mix until just combined. Roll into small balls.
Heat olive oil in a large skillet over medium-high heat. Add the meatballs and cook to brown on all sides. When the meatballs have developed a nice crust, remove them from the skillet.
Mince the other two cloves of garlic and add them to the pan drippings and stir until garlic blooms. Pour marinara into the skillet and add remaining Parmesan, bring sauce to simmer then add the meatballs back to the pan. Spoon sauce over the meatballs. Cover the pan with a lid and simmer meatballs for another 10-12 minutes, or until cooked through.
Top each meatball with mozzarella. Cover pan with lid or lose foil until the cheese is melted. Turn off heat.
Remove meatballs and plate
Top each meatball with a whole basil leave, folded, and pierce with a toothpick to serve.
Pour the extra marina sauce into a small bowl to serve with meatballs.