1Preheat oven to 400*F
Spray bottom and sides of a 9x13 rectangular baking dish with cooking spray.
Spread 3/4 cup of the pasta sauce in baking dish.Arrange half of the frozen ravioli in a single layer over the sauce; top with half of the remaining pasta sauce and half of the morzzarella cheese.
Spread spinach over cheese and repeat layer, starting with ravioli, remainder of sauce, and rest of cheese. Sprinkle with Parmesan cheese.
Cover with foil and bake for 30 minutes.Remove foil; bake uncovered for 10-15 minutes longer or until bubbly and hot in the center. Let stand for 10 minutes before serving.