Slice the bananas, then peel the mango and chop the flesh into pieces. Freeze both for at least 4 hours.Purée the frozen fruit with the almond milk and maple syrup in a blender until smooth. Add the almond milk slowly, you may need slightly more than the quantity specified above. Place in the freezer for another two hours.Shape the frozen mixture into ice cream scoops and place them on ice cream cones. Alternatively, serve the banana and mango nice cream in a glass dish.