Ingredients: 1 pound dry ziti pasta ,1 onion, chopped ,1 pound lean ground beef ,2 (26 ounce) jars spaghetti sauce ,6 ounces provolone cheese, sliced ,1 1/2 cups sour cream ,6 ounces mozzarella cheese, shredded ,2 tablespoons grated Parmesan cheese

Directions 
1.Bring a large pot of lightly salted water to a boil. Add ziti pasta, and cook until al dente, about 8 minutes; drain.
2.In a large skillet, brown onion and ground beef over medium heat. Add spaghetti sauce, and simmer 15 minutes.
3.Preheat the oven to 350 degrees F (175 degrees C). Butter a 9×13 inch baking dish. Layer as follows: 1/2 of the ziti, Provolone cheese, sour cream, 1/2 sauce mixture, remaining ziti, mozzarella cheese and remaining sauce mixture. Top with grated Parmesan cheese.
4.Bake for 30 minutes in the preheated oven, or until cheeses are melted.