Baked Ziti

Here's the baked ziti recipe we served at the family reunion. Hope you all enjoy!
Love,
Julie

Baked Ziti
from my friend, Kasey P.

1 pound dry ziti pasta (or penne)
1 onion, chopped (I did not add this at the reunion)
1 pound lean ground beef (or drain and rinse)
2 26-oz jars spaghetti sauce
6 ounces Provolone cheese, sliced
1 1/2 cups sour cream (I have used light sour cream with great results)
6 ounces mozzarella cheese, shredded
2 Tablespoons grated Parmesan cheese

Boil the pasta according to package directions, about 8 minutes or until al dente. Drain. In a large skillet, brown the onion and ground beef over medium heat. Add spaghetti sauce, and simmer 15 minutes.
Preheat the oven to 350 degrees. Grease a 9X13 inch baking dish (or two squares). Layer as follows: 1/2 of ziti, provolone cheese, sour cream, 1/2 sauce mixture, remaining ziti, mozarella cheese, and remaining sauce mixture. Top with grated Parmesan cheese.

Bake for 30 minutes in the preheated oven, or until cheeses are melted. Allow to stand for 15 minutes before serving. (This is important, or it will be soupy.) Serves 8-12. (Freezes well, too!)