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

Sauté finely chopped onion and minced garlic in a skillet over medium heat until translucent, about 5 minutes.

Combine ground beef, breadcrumbs, Parmesan cheese, parsley, basil, sautéed onion and garlic mixture, eggs, marinara sauce, Italian seasoning, salt, and pepper in a large mixing bowl and mix gently.

Shape the meat mixture into a rectangle about 1 inch thick on the parchment-lined baking sheet.

Spread shredded mozzarella cheese over the meat rectangle, leaving about a 1-inch border; add pepperoni or prosciutto if desired.

Carefully roll the meat rectangle tightly from one long side to the other, using parchment paper to assist, and place seam side down on the baking sheet.

Spoon additional marinara sauce generously over the top of the rolled meatloaf.

Bake for about 60 minutes, or until the internal temperature reaches 160°F (70°C) and the exterior is browned.

Allow the meatloaf to rest for 15-20 minutes before slicing to let juices redistribute.