The recipe calls for instant espresso. We could not locate. It calls for bananas, but I am not marring delicious mousse with bananas, thank you very much. It also calls for toasted hazelnuts and whipped cream on top, but when I tasted the amazingness of the mousse... well, I ate it without giving the hazelnuts (or whipped cream) another thought.
This recipe was just too easy. Use an electric mixer to mix 1/2 cup of Nutella into 1 cup of heavy cream until soft peaks form. Cool in the fridge for 2 hours. Try not to eat it all by yourself.