Preheat grill to medium or preheat oven to 450 degrees F. For each s'more, top one graham cracker square with one candy bar half, one marshmallow and another graham cracker square. Repeat with remaining graham crackers, candy and marshmallows.
Center s'mores individually on each sheet of Reynolds Wrap(R) Aluminum Foil.
Bring up foil sides. Double fold top and ends to seal packet, leaving room for heat circulation inside. Repeat to make four packets.