Baked Ziti

I made this last night and everyone loved it!

Baked Ziti

1 pound ziti
1 onion, chopped
1 pound lean ground beef
2 jars spaghetti sauce
6 ounces provolone cheese, sliced
1 1/2 cups sour cream
6 ounces mozzarella cheese, shredded
2 tablespoons grated Parmesan cheese

Cook ziti until al dente, drain and set aside. Cook the ground beef with the onion and drain fat. Add spaghetti sauce and let simmer for at least 15 minutes. In a 9 x 13 pan, layer 1/2 the ziti, provolone cheese, sour cream, 1/2 the sauce mixture, remaining ziti, mozzarella, remaining sauce and top with parmesan cheese.
Bake in a 350 degree oven for 30 minutes.

I found this recipe At See Jane in the Kitchen!
Notes from Jane:
This always gets rave reviews and every time I have made it for someone else they asked for the recipe. It is one of those dishes that taste even better the next day. I just made this for a birthday dinner and doubled it. I assembled it in the morning and put it in the fridge until it was time to eat. If you put it in the oven cold be sure to add at least 30 minutes to cooking time. Also, if you make it for a crowd and double it, only use three jars of sauce, not four.