Preheat your oven to 350°F (175°C). Lightly grease a loaf pan or line a baking sheet with parchment.

In a large bowl, combine the ground meat, breadcrumbs, beaten eggs, milk, onion, garlic, Parmesan, tomato paste, Italian seasoning, salt, and pepper. Mix gently until evenly incorporated.

On a clean work surface, pat the meat mixture into a rough rectangle about 10 by 6 inches.

Sprinkle the shredded mozzarella in a line down the center of the rectangle, leaving about an inch of meat buffer on each long side.

Fold the long sides of the meat over the cheese and pinch the seams together to seal.

Transfer seam-side down into the prepared loaf pan or onto the baking sheet and smooth the top with wet hands.

Spread the 1/2 cup marinara sauce over the top, then sprinkle with additional Parmesan and a pinch of dried basil.

Bake for about 60 to 75 minutes, until the internal temperature reaches 160°F (71°C).

Let the meatloaf rest for 10 minutes before slicing.