Preheat your oven to 350°F (175°C) and prepare a 9x13 baking dish by lining it with parchment paper.

In a skillet over medium heat, add olive oil and sauté diced red onion and red bell pepper for about 5 minutes until softened. Add minced garlic and cook for another minute.

In a large mixing bowl, combine ground beef, breadcrumbs, Parmesan cheese, egg, tomato paste, cool sautéed vegetables, salt, pepper, and parsley. Mix until fully combined.

Shape the meat mixture into a rectangle on the parchment-lined baking dish, approximately 8 inches by 15 inches.

Layer slices of deli ham, fresh basil leaves, and shredded mozzarella cheese on the meat mixture, leaving a small border around the edges.

Roll the meatloaf tightly using parchment paper as a guide and seal the edges to keep the filling secure.

Place the seam side down on a baking sheet and bake in the oven for 1 hour or until the internal temperature reaches 160°F (71°C).

Let the meatloaf rest for about 10 minutes before slicing.

Serve hot with marinara sauce on the side.