1 pound of Italian sausage (I use a combination of sweet and mild)
1 diced onion
16oz box of Ziti Pasta
2-26 oz jars of Spaghetti sauce (or 5 and half cups of homemade sauce)
6oz of Provolone cheese ( I always use a full pack usually 8 oz)
1 and half cups of sour cream
8 oz of Mozzarella  cheese
Parmesan Cheese

Bring pot of water to boil and place in pasta, cook for 8 minutes until the pasta is al diene.
Combine sausage and onion and brown, add sauce and let simmer for 15 minutes
Butter a 9 x 13 pan Layer as follows:  1/2 ziti pasta, provolone cheese, sour cream, 1/2 sausage mixture, remaining ziti pasta, mozzarella cheese , remaining sausage mixture . (I usually freeze at this point). Top with parmesan cheese.  (This makes a very full dish, I place a pan underneath in the oven for overflow.

If using from frozen, unthaw completely.  Bake in a preheated oven at 350 for 30 minutes.

As you read, it is very easy to make a double batch and freeze one!