For the Frozen Cappuccino, sweeten the coffee to taste with the sugar. Stir in the vanilla sugar. Pour some crushed ice into 4 glasses.
Mix the milk with the whipped cream and the coffee very well with a blender or hand blender. It should form a foam.
Pour the Frozen Cappuccino over the ice cream and dust with a little cinnamon and serve immediately. You can also add 2 cl of Amaretto, Baileys or whiskey, depending on your taste.