For the banana in a caramel shirt, in a small, preferably ceramic-coated, pan, melt butter. Add granulated sugar and stir until the sugar turns brown.
Then add the peeled banana to the pan and very quickly turn it in the caramel ( works best with wooden tongs or similar).
Then immediately pour the whipped cream so that the sugar does not burn. Sprinkle with pistachios. Remove the pan from the heat and arrange the banana in the caramel shirt nicely on plates.
For the banana in the caramel shirt rather use hard, still unripe bananas, because if the bananas are already too ripe, they disintegrate very quickly.