Begin by adding the Nutella to a large mixing bowl and set it aside.

In a separate microwave-safe bowl, add 1/4 cup of heavy whipping cream. Heat it in the microwave for 45–60 seconds, until the cream is hot and bubbling.

Carefully pour the hot cream over the Nutella. Allow it to sit for 1 minute to soften, then stir until smooth and fully combined.

Once cooled, pour the remaining heavy cream into another mixing bowl. Using a handheld mixer, start at low speed and mix until thick and stiff peaks form, about 3-5 minutes.

Gently fold 1/3 of the whipped cream into the cooled Nutella mixture until just combined. Repeat with another third, and finally fold in the remaining whipped cream.

Spoon the mousse into ramekins or individual serving dishes. Refrigerate for at least 2 hours before serving.

When ready, top with additional whipped cream, if desired, and serve chilled.