01 -
Preheat oven to 190°C. In a large saucepan, cook spaghetti in salted boiling water until al dente. Drain well and set aside.
02 -
While pasta is cooking, heat a large skillet over medium heat. Brown the ground beef and ground sausage, adding diced onion as the meat cooks. Drain excess fat. Return meat and onions to skillet.
03 -
Add tomato sauce, tomato paste, Italian seasoning, minced garlic, salt, and black pepper to the meat mixture. Stir thoroughly and simmer for 5 to 8 minutes. Incorporate cooked spaghetti and remove from heat.
04 -
Slice the Italian bread loaf in half lengthwise using a bread knife. Hollow out the centers of each half to create ample space for filling. Brush the interior with butter and liberally sprinkle with garlic powder. Toast in the preheated oven until lightly golden.
05 -
Fill the toasted bread halves completely with the spaghetti and meat sauce mixture. Sprinkle each half with equal portions of Parmesan and mozzarella cheeses.
06 -
Return filled loaves to oven and bake for 15 to 20 minutes, or until cheeses are melted and golden. Let rest briefly, then use a bread knife to slice and serve warm.