Slightly undercook ziti, about 8 minutes.
Drain, reserving 1 cup of the pasta cooking water, cover and set aside.
Preheat oven to 375˚F.
Heat 5 cups spaghetti sauce and pasta water. Simmer for 10 minutes.
Mix sauce with cooked ziti.
Spoon half of ziti mixture into 13″ x 9″ x 2″ baking dish.
Sprinkle with mozzarella and 1/2 cup Parmesan cheese.
Top with remaining ziti mixture and remaining 1 cup of spaghetti sauce.
Sprinkle with remaining 1/2 cup Parmesan cheese.
Bake 25-30 minutes or until heated through.
