Place the round peppermint candies in a blender. Whirl until the candies are pulverized fine. Add the crushed ice, frozen coffee yogurt, skim milk and chocolate syrup to the candies in the blender. With on/off pulses, blend until the mixture is thick and smooth.
Pour into 4 chilled tall glasses and serve. Garnish each drink with a peppermint stick if you wish.