In a large bowl, combine the cooked pasta, ricotta cheese, 1 cup mozzarella cheese, parmesan cheese and 2 cups of the pasta sauce. Mix well, then pour this mixture into a 8x11 inch casserole dish.
Drizzle the remaining pasta sauce on top of this mixture, then spread the last cup of mozzarella cheese over the top. Bake uncovered for 30 minutes.