Cut the avocado and banana into chunks. Blend the fruit with cocoa until you have a soft and smooth mousse.
Divide the mousse into 4 small cups and top with chopped hazelnuts.
Let the mousse rest in the fridge for at least half an hour before serving.
Resting in the fridge before serving is not mandatory, but makes the mousse fresh and thick.
Add 2 or 3 tbsp of agave nectar to make the mousse sweeter, if you like.This raw vegan chocolate mousse keeps well in the fridge for a couple of days, close well the jars in plastic wrap.