Defrost the bananas a little ahead of time so they are easier to blend. The riper they are the sweeter your ice cream will be.
Break up the banana and blend it with the cacao powder, add in the vanilla and blend well.
When you start to get an ice cream-like texture stick the mixture into the freezer.
It will need at least 5 hours to freeze properly, but if you leave it overnight it will be great and ready to go the next day. Add your favorite topping: fruit, nut and seed granola, or some small cacao bites and start eating!