Mix caramel spread and butter together. Pour into a piping bag. Peel bananas. Cut each banana into slices about 1⁄2 cm thick. Spray cream onto half of the banana slices. Cover with the rest of the banana slices.
Stick the wooden stems into the banana towers. Put them in a cool place for about 30 minutes.
Chop the chocolate coating for the glaze. Heat the cream and remove from the heat. Melt the couverture and coconut oil in it while stirring. Dip the turrets into the icing, holding the pot at a slight angle. Drain a little, place on baking paper and let dry.