Have a large piece of foil on hand. Place the sliced bananas in the center, followed by marshmallows, then chocolate. Close the foil tightly around the ingredients.

Build a fire and let it burn down until you have a few flames and a solid bed of coals. Place grill over coals and let the grill heat up for a few minutes.

Place the foil packet on the grill and cook until you begin to hear the packet sizzle, then continue to cook for about 5 minutes. Move packet to a cooler portion of the grill and let cook for another 3–4 minutes.

Carefully remove the package from the grill, then serve immediately with lots of graham crackers (or other cookies) for dipping.