01 -
Set oven to 190°C and allow to fully preheat.
02 -
In a large mixing bowl, combine ground beef, ground Italian sausage, onion, garlic, bread crumbs, eggs, Parmesan cheese, Italian seasoning, and parsley. Add milk, salt, and black pepper. Mix thoroughly until well incorporated but avoid overworking the meat.
03 -
Transfer the meat mixture to a parchment-lined baking tray. Shape into a 23 x 30 cm rectangle.
04 -
Create a long well down the center of the meat rectangle. Evenly distribute mozzarella cheese, chopped spinach if using, and 60 ml marinara sauce within the well.
05 -
Carefully fold the meat over the filling, pressing the edges to seal and forming a compact loaf.
06 -
Spread 120 ml marinara sauce over the top of the loaf and sprinkle with 25 g grated Parmesan cheese.
07 -
Place the loaf in the center of the oven and bake for 45 to 55 minutes, or until the internal temperature reaches 71°C.
08 -
Remove from oven and let rest for 10 minutes before slicing. Serve warm, with additional marinara sauce if preferred.