Select two avocados of medium-large size and ripe. Unripened avocados may leave traces of fiber in the mousse. In this case, they will give a more vegetal taste and texture.
Try to use grade C maple syrup. It is the purest and more dense than grades A or B which are lighter, sweeter and contain less amounts of minerals.
Maple syrup can be replaced by agave syrup but the final taste will be slightly modified.
Once the mousse is blended, check texture and add a splash of water to make it lighter if necessary.
The mousse flavor will be rounded up in the fridge and will be less vegetal after one or two days.