Put the pitted and split plums (do not need to be peeled) in a tall mixing bowl and puree with the hand blender. Then add the yoghurt and milk and puree everything together again really nicely.
Finally add sugar and cinnamon. I always make the drink with little sugar - but that`s up to everyone. One likes it sweeter, the other doesn`t.
If the ingredients have been chilled properly before preparation, the shake is particularly tasty and the ideal drink even for hot summer days.