Preheat oven to 350 degrees F (175 degrees C).

Bring a large pot of lightly salted water to a boil.

Add ziti pasta and cook for 8 to 10 minutes or until al dente.

Drain pasta thoroughly.

In a large skillet, brown ground beef over medium heat.

Add chopped onion to the skillet.

Saute onion until tender.

Drain off any excess fat from the skillet.

Add spaghetti sauce to the skillet with the beef and onions.

Simmer the sauce for about 15 minutes, stirring occasionally.

Lightly grease a 2 quart baking dish.

Place about half of the cooked ziti pasta in the baking dish.

Top the pasta with a layer of provolone and mozzarella cheese slices.

Spread half of the spaghetti sauce mixture evenly over the cheese layer.

Spread half of the sour cream evenly over the sauce layer.

Cover with the remaining ziti pasta.

Top with the remaining cheese slices.

Spread the remaining sauce mixture evenly over the cheese.

Sprinkle a layer of grated Parmesan cheese over the sauce.

Sprinkle chopped fresh basil over the Parmesan cheese.

Bake in the preheated oven for about 30 minutes.

Bake until the cheese and sauce are bubbly and golden brown.

Let stand for a few minutes before serving.

Serve hot.