Butter two Soufflé ramekins and sprinkle with cocoa powder, knocking out excess.
3. Step
In a medium bowl, mix Nutella and 2 egg yolks.
4. Step
In a separate medium bowl, whisk 2 egg whites until foam starts to form. Add sugar and continue mixing until they hold stiff peaks.
5. Step
Fold ⅓ of the whites into the Nutella mixture until fully incorporated. Add the remaining whites to the mixture and fold gently, but thoroughly until the mixture is smooth.
6. Step
Pour the mixture in the ramekins, clean the rims so the Soufflé rises evenly, and bake for 15 - 17 minutes.