Cook the pasta according to package directions. Meanwhile, cook the beef, sausage, mushrooms, onion and green pepper over medium heat until meat is no longer pink. Drain
Drain pasta; add to the meat mixture. Stir in the tomatoes, sausage and garlic spaghetti sauce, salsa, and pepperoni.
Divide half of the pasta mixture between2 greased 13 x 9 baking dishes. Sprinkle each with 1 C mozzarella and 1/3 C Parmesan. Spread 3/4 C of the three cheese spaghetti sauce over each. Top with remaining pasta mixture and spaghetti sauce.Sprinkle with remaining cheeses.
Cover and Freeze one casserole for up to 3 months. Cover and bake the remaining casserole at 350* for 25 minutes. Uncover, bake 10 minutes longer or until cheese is melted