Slice each banana lengthwise and squeeze the ends so that it opens up a bit. It is best to find ones that are already slightly brown and softer to do this.
Push the chocolate chips down into the bottom of the bananas. Then push small marshmallows down on top of those and if you are a nut lover then put a layer of crushed peanuts, walnuts, or almonds in between the two layers.
Make sure all fillings are secure and won't fall out so don't overstuff.
Put on the BBQ after your meats are done. Wait until the heat has died down and can use wads of foil on either side so they don't fall over. Grill until they get really warm and start to brown…and everything melts.