Hold a banana so that it curls upwards in your hand. Peel back just the top segment of the peel; do not peel all the way off. With a spoon, carefully scoop out the center of the banana creating a hollowed canoe shape banana; do not scoop down to the bottom peel. Eat the scooped out banana. Cut marshmallows into fourths and break the chocolate bar into segments. Place a marshmallow piece and chocolate piece in the banana groove alternating marshmallow, chocolate, marshmallow, chocolate, etc. until the space is filled up. Replace the peeling, covering the filling up. Wrap the banana in foil and place next to the camp fire for about 15 minutes. (You can also do this in the oven at 350 degrees F. for 10 minutes) Remove the foil, peel back the pre-peeled segment of the peel and eat with a spoon.