If using meat, brown the ground beef in a skillet over medium-high heat until no longer pink; drain.
Mix spaghetti sauce, tomatoes, water and browned meat, if using.
Spoon 1 cup of sauce mixture onto bottom of 9x13 baking dish. Layer 1/3 ravioli and 1/3 cheese over sauce mixture. Repeat layers twice. Top with remaining sauce mixture.
Sprinkle with Parmesan cheese.
Cover and bake 30 minutes.
Uncover and bake 15 minutes more or until ravioli is tender and heated through.
Let stand 10 minutes.