Place a heatproof bowl over a pan of simmering water, making sure the base doesn’t touch the water. Break the chocolate into the bowl and allow it to melt, then set aside to cool slightly. Halve and destone the avocados, then scoop the flesh into a food processor, discarding the skins. Add the remaining ingredients and pulse for a few seconds. Scrape down the sides with a spatula, then pulse again to combine. Pour in the cooled chocolate, then pulse a final time until creamy and smooth. Divide the mixture between six small bowls, then pop in the fridge to chill for at least 30 minutes. Serve with an extra grating of chocolate and a fresh fruit salad.