Caramelise the sugar in a small pot until golden brown. Add 5 tablespoons of water and simmer until the caramel has dissolved. Let the caramel cool down. Roughly chop the chocolate and melt in a bowl on a warm water bath. As soon as the caramel is cold, whip the cream until stiff, adding the caramel.
Peel the bananas and cut them diagonally into slices. Arrange the slices on 4 plates. Pour the cream into a piping bag with a star-shaped spout and squirt onto the bananas. Halve the wafer rolls. Pour a teaspoon of chocolate over the cream and decorate with wafer rolls