3 (8 oz) packages frozen ravioli (or 1 25 ounce bag)
36 ounces marinara sauce
1 (14 ounce) package fully cooked miniature (cocktail-size) meatballs
3 cups shredded mozzarella cheese
1/3 cup parmesan cheese
Spray a 13x9" baking dish (or two 8x8" dishes) with cooking spray. Pour about 1/3 of the marinara sauce (12 ounces) into the prepared baking dish to cover bottom. Arrange half of the frozen ravioli in a single layer over sauce. Top with half of the meatballs. Pour another 1/3 of marinara sauce over top. Sprinkle with 1/2 of the mozzarella cheese. Repeat layers once more, starting with ravioli. Sprinkle parmesan cheese on top. Cover tightly with foil & freeze.
Thaw completely. Bake, covered, for 20 minutes. Remove foil & bake, uncovered, for 20-25 minutes or until bubbly and hot in center. Let stand 10 minutes before serving.