Break the milk slices into small pieces and puree them very finely with the hand blender until a creamy mixture is obtained. Then add the ice cream and milk and mix again.
Pour the shake into a glass, whip the cream until stiff and use a piping nozzle to put the icing on the shake. Dust with cocoa or decorate with chocolate shavings and serve with a straw.
TIP:
If you like it even more vanilla, you can mix a little vanilla sugar into the shake.