Baked Ziti

I always make this without the beef. Simple and yummy.

1 lb dry ziti pasta
1 onion, chopped
1 lb lean ground beef (optional)
1 (26 oz) jars spaghetti sauce
6 oz provolone cheese, sliced (optional)
1 1/2 cup sour cream
6 oz mozzerella cheese, shredded
2 Tbls grated parmesan cheese

Boil pasta until al dente, about 8 minutes; drain.
In a large skillet, brown onion and beef over medium high heat. Add spaghetti sauce, and simmer 15 minutes. Add sour cream to spaghetti mixture. (I skip all of that and simply add the onions and sour cream to the spaghetti sauce and call it good).

Butter a 9x13 inch dish. Layer as follows: 1/2 of the ziti, provolone cheese, 1/2 the sauce mixture, remaining ziti, mozzarella, and remaining sauce mixture. Top with grated parmesan cheese.

Bake at 350 degrees for 30 minutes or until the cheese melts.