Cook spaghetti according to package directions and drain. Return the spaghetti to the pot and stir in butter, Parmesan cheese, and eggs.
Press spaghetti mixture into a buttered ceramic pie plate to form the crust.
In a skillet, cook the Italian sausage, onion, and green pepper until vegetables are tender and meat is browned. Stir in diced tomatoes, tomato paste, sugar, oregano, and garlic salt. Heat through.
Spread cottage cheese inside the spaghetti crust. Top the cottage cheese with the sausage and tomato mixture.
Bake uncovered in a 350℉ oven for 20 minutes.
Sprinkle mozzarella cheese over the top. Bake for an additional 5 minutes or until the cheese is melted and gooey.
Recipe Notes
Make ahead:This spaghetti pie can also be prepared ahead of time and refrigerated. Cover the spaghetti crust edges with foil, and bake cold from the fridge at 350℉ cold from the fridge for 1 hour. Sprinkle mozzarella cheese over the top. Bake for an additional 5 minutes or until the cheese is melted and gooey.Storage: Leftovers can be stored in an airtight container in the refrigerator for up to 4 days or in the freezer for 3 months.