Slice the bananas and put them on a baking tray covered in non-stick baking paper. Freeze for at least 2 hours
Put the milk, bananas, blueberries and almond extract in a blender or food processor. Blitz until smooth. You will need to keep stopping and scraping down the sides to make sure everything gets fully blended.
Eat immediately or put in a freezer proof container and put back in the freezer until you want to eat it.
Nutritional information is approximate and a guideline only.