Preheat oven to 375 °F (190 °C). Line a loaf pan or shape meatloaf on a rimmed baking sheet.

In a small bowl, soak breadcrumbs with milk, allowing them to soften (~5 min).

In a large mixing bowl, whisk together eggs, Parmesan, onion, garlic, parsley, oregano, basil, salt, and pepper. Stir in soaked breadcrumbs.

Add ground beef to the bowl. Using clean hands, mix gently until evenly combined—don’t overwork.

On a clean sheet of parchment or your counter lightly oiled, pat half the meat mixture into a rectangular loaf shape (~9×5″).

Arrange mozzarella sticks or cubes down the center, leaving an inch on each end.

Gently cover with the remaining meat mixture, sealing the edges and forming a loaf around the cheese.

Place loaf in pan (seam side down) or on baking sheet. Spread ½ cup marinara sauce over the top.

Bake for 50–60 minutes, until meatloaf is cooked through (internal temperature about 160 °F/71 °C).

During the last 10 minutes, spoon extra marinara sauce over the top to form a nice glaze.

Remove from oven and let rest 10 minutes before slicing—this helps keep cheese contained.