1. Preheat oven to 375°F (190°C).
2. In a bowl, combine ground beef, breadcrumbs, Parmesan cheese, egg, garlic, Italian seasoning, salt, and pepper. Mix well and shape into 12 meatballs.
3. Heat a skillet over medium heat and brown the meatballs on all sides (they don’t need to cook through).
4. In a 9×9-inch baking dish, pour 1 cup of marinara sauce and arrange the browned meatballs on top.
5. Cover the meatballs with the remaining marinara sauce and sprinkle mozzarella cheese evenly over the dish.
6. Bake for 20-25 minutes, or until the cheese is bubbly and golden.
7. Remove from oven and garnish with fresh parsley before serving.