To avoid wasting half a can of soup, I will sometimes double this recipe and freeze one of the pans before baking.
1 jar of spaghetti sauce
6 oz. spaghetti
1 cup shredded cheddar cheese
1 cup shredded Mozzarella cheese
1/2 can mushroom soup
2 Tablespoons water
2 Tablespoons Parmesan cheese
Boil spaghetti according to package directions; drain. Place half of the spaghetti in a greased square baking dish. Top with half of the spaghetti sauce. Sprinkle with the cheddar cheese. Repeat layers, except end with Mozzarella cheese.
Mix the soup and water until smooth; pour over the casserole. Sprinkle with Parmesan cheese.
Bake, uncovered, at 350 degrees for 30-35 minutes, or until heated through.