Preheat oven to 450°F or grill to medium-high
Center one chicken breast half on each sheet of Reynolds Wrap® Aluminum Foil. Spoon spaghetti sauce over the chicken. Top with zucchini. Sprinkle with Parmesan cheese.
Bring up foil sides. Double fold top and ends to seal packet, leaving room for heat circulation inside. Repeat to make 2 packets.
Bake 18 to 22 minutes on a cookie sheet in the oven or Grill 12 to 14 minutes in covered grill. Springle with Mozzarella cheese before serving.