Combine the heavy cream and espresso in a small mixing bowl. Stir until dissolved, about 5 minutes.
Add the espresso mixture to the standing mixer, along with Nutella. Mix with the whisk attachment on medium for 1 minute.
Continue beating until it looks fluffy (soft peaks), about 1 minute.
Transfer to a serving bowl and refrigerate for 2 hours.
Garnish with with the toasted hazelnuts, whipped cream, and bananas.