Creating a stuffed Italian meatloaf is straightforward if you follow these easy steps:

1. Preheat the Oven: Preheat your oven to 375°F (190°C).
2. Prepare the Baking Dish: Lightly grease a loaf pan or line it with parchment paper for easy removal.
3. Mix the Ingredients: In a large mixing bowl, combine the ground beef, breadcrumbs, Parmesan cheese, mozzarella cheese, eggs, milk, parsley, garlic, oregano, basil, salt, and pepper. Mix until well incorporated.
4. Create the Stuffing: Form half of the meat mixture into a rectangle on a sheet of plastic wrap or parchment paper. Make it about 1-inch thick.
5. Add the Cheese: Sprinkle the remaining mozzarella cheese in the center of the meat mixture. You can also add any optional fillings, such as cooked spinach or sautéed mushrooms.
6. Roll and Seal: Carefully roll the meat mixture using the plastic wrap to help you and seal the edges. Ensure the cheese and other fillings are fully encased.
7. Shape the Loaf: Place the rolled meatloaf into the prepared baking dish, seam side down. Shape it to form a loaf shape.
8. Top with Marinara Sauce: Spread marinara sauce generously over the top of the meatloaf, ensuring it’s evenly covered.
9. Bake: Place in the preheated oven and bake for about 45 minutes, or until the meatloaf reaches an internal temperature of 160°F (71°C).
10. Rest and Serve: Remove from the oven and allow it to rest for 10-15 minutes before slicing. This helps the juices redistribute.

Following these instructions will lead you to create a mouthwatering stuffed Italian meatloaf that impresses.