Baked Ziti

This is a recipe that has made the rounds on a message board I am a member of. It's gotten rave reviews over the years, but tonight was the first time that I'd ever tried it. I am happy to report that the rumors are true, it's super yummy. Three kinds of cheese, plus sour cream, what's not to love?! Definitely comfort food, but it's perfect for making ahead and freezing. My notes in brackets.

Ingredients:
1 pound dry ziti pasta
1 onion, chopped [I added 2 cloves of garlic]
1 pound lean ground beef
2 26 ounce jars spaghetti sauce [I only used one jar of sauce since I didn't read carefully, it came out fine]
6 ounce provolone cheese sliced
1 ½ cup sour cream [reduced fat works just as well]
6 ounce mozzarella cheese, shredded
2 tablespoon Parmesan cheese, grated

Procedure:
1. Bring a large pot of lightly salted 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. Layer as follows: Half of the ziti, Provolone cheese, sour cream, half of the sauce mixture, remaining ziti, mozzarella cheese and remaining sauce mixture. Top with grated Parmesan cheese.
4. Bake for 30 minutes in the preheated oven, or until cheeses are melted. Serves 6-8 regular people, 4-6 hungry people.