Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper or lightly grease it.

In a medium skillet over medium heat, add olive oil and sauté the finely chopped onion and minced garlic for about 5 minutes until translucent.

In a large mixing bowl, combine ground beef, breadcrumbs, Parmesan cheese, chopped parsley, chopped basil, sautéed onion and garlic, eggs, marinara sauce, Italian seasoning, and salt and pepper. Mix gently until combined.

Turn the meat mixture onto the prepared parchment paper and shape it into a rectangle, about 1 inch thick.

Sprinkle shredded mozzarella cheese over the meat layer, leaving a slight border. Optionally, layer sliced pepperoni or prosciutto over the cheese.

Using the parchment paper, roll the meat mixture tightly to enclose the cheese and optional meats, sealing the ends as you go.

Place the rolled meatloaf seam-side down on the baking sheet. Drizzle additional marinara sauce over the top.

Bake for about 60 minutes until the internal temperature reaches 160°F (70°C).

Once baked, let the Stuffed Italian Meatloaf rest for 15-20 minutes before slicing.