Cut a slit through the middle of the bananas but don’t go all the way down. Divide the chocolate pieces, marshmallows and peanut butter among them.
Individually wrap each banana in baking paper then foil. Carefully place cut-side up in the barbecue embers and cook for 20-25 minutes. (Or if you prefer, bake in a hot oven for the same length of time.)
Unwrap the bananas, top with scoops of the ice cream and scatter over the roasted peanuts.