Baked Ziti Recipe

Cook pasta according to package directions. Drain. Brown onion and ground beef over medium heat. Add spaghetti sauce, and simmer 15 minutes. Layer as follows in buttered baking dish: 1/2 of the ziti, provolone cheese, sour cream, 1/2 spaghetti sauce, remaining ziti, mozzarella cheese, and remaining sauce. Top with grated Parmesan cheese. Bake at 350 degrees F for 30 minutes, or until cheeses are melted. Makes 4 servings.