In a Dutch oven, cook beef and onions over medium heat until meat is no longer pink; drain. Stir in the bacon, tomato sauce, tomatoes, sugar and salt; cook until heated through.
Spread 1 cup meat sauce in each of two greased 13-in. x 9-in. baking dishes. Layer four noodles, 1-2/3 cups meat sauce, 1-1/3 cups cheese in each dish. Repeat layers twice.
Cover and bake at 350° for 40 minutes. Uncover; bake 5-10 minutes longer or until bubbly. Let stand for 15 minutes before cutting. Yield: 2 casseroles (12 servings each).