Manicotti Cheese Bake

Why I Love This Recipe
I'm not sure where this recipe came from. I found it with my mother in laws cookbooks but its not in her writing. She passed away before I met my husband, so I can't ask her. Maybe my sister in law wrote it down for her mom?
Ingredients You'll Need
1/2 lb ground beef
2 - 3 italian sausages
1/2 cup chopped onion
1/4 cup bell pepper, chopped
1 12 oz can tomato puree
1 tsp sugar
3/4 tsp basil
3/4 tsp oregano
2 cloves garlic, minced
1 pint ricotta cheese
1/4 cup grated parmesan cheese
1 cup grated mozzarella cheese
1 egg
8 - 10 manicotti shells
Directions
Preheat over to 350'
Brown ground beef, onion and bell pepper.
Brown Sausage in a separate pan with a little water. Let simmer
Add tomato puree, sugar, basil, oregano and garlic to browned beef; cook for 10 minutes
Slice sausage and add to sauce; cook 10 minutes more.
Cook manicotti according to package directions
Mix ricotta cheese, parmesan cheese, 3/4 cup mozzarella cheese and egg.
Fill cooked manicotti shells with cheese mixture.
Pour 1/2 of the sauce in a casserole dish. Place filled manicotti shells in dish. Pour remaining sauce over.
Cook for oven for 20 minutes. Sprinkle remaining mozzarella cheese on top and cook for 10 minutes