For the banana flavoring, place 4 bananas side by side in a fireproof dish with the inside of the curvature facing up and pierce with 2 skewers.
Using a knife, cut through the skin of the bananas on the inside of the curvature as well as the flesh of the fruit 1 cm deep.
Press chocolate pieces into this slit, sprinkle a little sugar on top and pour rum (or other alcohol) into the slit.
Place on the grill or in the oven. Grill or bake at about 180 °C until the chocolate has melted.
Arrange banana flavored dessert and serve.