Place Nutella in a microwave-safe bowl and heat it for 30 seconds. Set it aside to let it cool.

Place the heavy whipping cream in a chilled bowl. Using an electric mixer, whip until stiff peaks form.

Using a rubber spatula, gently fold the Nutella into the whipped cream in two separate parts until completely incorporated.

Spoon or pipe the mousse into the desired serving dish or dishes, and refrigerate for 2-4 hours to set.