Banana's, as many as you want.
Chocolate, Cadbury family block style.
Don't peel bananas. Make a single cut along the banana skin from just before each end. Do this along the inside of the bend. Carefully open up the banana skin. Break up the chocolate into rows. Push the chocolate into the cut you just made in banana skin. Use one to two rows of chocolate and marshmallows. Wrap each banana separately in aluminium foil. Carefully place each foil wrapped banana near the fire, don't bury it in coals. Leave in fire for 10 to 20 minutes until the banana is nice and warn and the chocolate is melted.
Remove the foil. Place the banana on a plate and peel the skin away, eat directly off the skin.