Banana boats were always a winner at Girl Scout camp-outs.
For each one you'll need:
1 square of aluminum foil
chocolate chips, or leftover chocolate squares from S'mores (I suppose you can also use peanut butter chips. They didn't have those around when I was a leader...)
mini-marshmallows (sorry, rockey_, had to bring them up )
Place banana on foil, make a cut from stem-to-blossom-end right through the skin, about half-way through the banana.
Shove chocolate and marshmallows into the cut in the banana.
Draw foil up around banana so that the seam is on the topside. I bunch it up so that it forms a ridge that you can grab it by with tongs.
Let it cool a bit, unwrap the foil, and eat with a spoon.
Have fun camping!