Combine sauce, 1/2 cup Mozzarella cheese and Parmesan cheese in large bowl. Stir in vegetables and hot ziti.
Spoon pasta mixture into 13 x 9-inch casserole; tightly cover with aluminum foil. Bake 25 minutes covered. Sprinkle with remaining 1/2 cup Mozzarella cheese; bake uncovered until heated through, about 5 minutes.