Preheat oven to 350 degrees.

Cook pasta according to package directions. Drain.

In the meantime, brown the ground beef with onion and cook until softened. Mix in spaghetti sauce and allow to simmer for 15 minutes. Mix in sour cream. Add the drained pasta and stir to coat.

Pour half of the pasta into the baking dish. Top with half of the provolone and half of the Mozzarella. Pour in the remaining pasta and top with the remaining provolone and mozzarella. Sprinkle parmesan over top.

Bake at 350 degrees for about 30 minutes until the cheese is melted and bubbly. Sprinkle with chopped parsley before serving. Serves 4-6.