Place thecacao nibs in a mini-blender and blitz to give a rough crumb. Tip them into a small bowl and set aside. Wipe the blender bowl and blade of crumbs.
Halve the avocados, discard their stones and scoop the flesh into the blender. Add the maple syrup, cocoa or raw cacao powder, vanilla extract and peppermint extract, and blitz to give a thick, silky smooth mousse. Cut the tip off the piping bag to give a 2cm opening. Scoop the mixture into the bag and then pipe it evenly between the serving glasses. Alternatively, use two small spoons to scoop and scrape the mixture into the glasses.
This can be eaten straight away or it can be made up to two days in advance and kept covered in the fridge. When ready to serve, sprinkle the cacao nib crumbs evenly over the top of each one. Stick a mint stalk into the centre of each one, so it sits upright as if growing, and serve.
For a twist…
Instead of the peppermint extract, add to the blender either the finely grated zest of 1 large orange or a 2.5 cm piece of fresh ginger that has been peeled and finely grated.