heat oven to 375 spray a 13x9x2 inch glass casserole dish with cooking spray.
stir the sauce and water in a large bowl. spread 1 cup of sauce in the prepared dish. top with 1/2 the ravioli. 3/4 c of the mozzarella cheese and 1 cup of the sauce. top with remaining ravioli and sauce, and cover.
bake for 35 mins, uncover the dish and top with remaining cheese.
bake for 10 more mins or until hot and bubbly. take out. let stand 10 mins before serving.