Baked Ziti

1 pound dry ziti pasta
1 onion, chopped
1 pound lean ground beef
2 (26 oz.) jars of spaghetti sauce
6 ounces of provolone cheese, sliced
1 1/2 cups sour cream
6 ounces mozzarella cheese, shredded
2 Tbsp. grated Parmesan cheese

Directions:
1. Bring a large pot of boiling 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. Butter a 9X13 inch baking dish (or two 8x8 dishes). Kerri's note: there is no way this will fit in my 9x13 pans. I can do a 9x13 plus an 8x8. Layer as follows: 1/2 of the ziti, Provolone cheese, sour cream, 1/2 of the sauce mixture, 4 oz mozzarella, remaining ziti, remaining sauce. Top with 2 oz mozzarella and grated Parmesan cheese.

4. Bake for 30 minutes in the preheated oven, or until cheeses are melted. Serves 8 or more (this recipe freezes well. I cook the pasta ½ of the recommended time if freezing).