1. Heat oven to 375 degrees F. Coat 2-quart casserole dish with cooking spray. Cook noodles according to package directions. Reserve 1/2 cup of cooking liquid. Drain noodles; rinse under cold water.
2. While noodles are cooking, combine ricotta cheese, 1 cup mozzarella cheese, and vegetables.
3. In large bowl, mix noodles, marinara sauce, and reserved cooking liquid. Place 3 cups noodle mixture in casserole dish. Spread ricotta mixture over noodles. Top with remaining noodles and sprinkle with remaining mozzarella cheese.
4. Bake 20 minutes, or until cheese has melted.