Preheat oven to 450 degrees F or grill to medium-high.
Center sweet potatoes, apples and cranberries on sheet of Reynolds Wrap(R) Heavy Duty Aluminum Foil. Sprinkle with brown sugar. Combine butter and cinnamon; drizzle over brown sugar.
Bring up foil sides. Double fold top and ends to seal making one large foil packet, leaving room for heat circulation inside.
Bake 25 to 30 minutes on a cookie sheet or in a 13x9x2-inch dish OR GRILL 20 to 25 minutes in covered grill until sweet potatoes are tender.
