Cut the bananas into pieces and let them freeze in the freezer bag for at least 3 hours or overnight. For preparation, let the frozen banana slices thaw for about 5 minutes in advance.
Put all ingredients in a powerful blender and puree to a smooth, creamy mass.
Garnish with the toppings
Note: This works less well with a hand blender because it is not as powerful as a stand mixer. When using a hand blender, the frozen fruits must be thawed longer so that they can be pureed well.