Chop/break chocolate bar into small pieces. Melt in a small heavy saucepan or in top of a double-boiler over simmering water. Stir occasionally until melted.

Add hot chocolate mix and sugar, stirring constantly until combined (consistency will be smooth). Remove from heat. Slowly add 1/2 cup milk, stirring until well-mixed. Let cool to room temperature (about 15 to 30 minutes).

In a blender, add remaining milk, creamy chocolate mixture and ice. Blend on high speed until smooth and the consistency of a frozen daiquiri. Immediately pour into one giant goblet (to share) or in 4 small cups. Top with whipped cream and chocolate shavings, if desired. 

Calories: 229, Fat: 12 g (7 g Saturated Fat), Cholesterol: 16 mg, Sodium: 89 mg, Carbohydrates: 30 g, Fiber: 1 g, Protein: 5 g.