Start by chopping the chocolate into small pieces. Place it in the top of a double boiler over simmering water and stir until melted. Add the sugar and hot chocolate mix and continue stirring until incorporated.
Remove from heat and slowly add the heavy cream, whisking until smooth. Let it cool to room temperature.
Transfer the chocolate mix to the jar of a powerful blender and add the milk and ice. Blend on high speed until smooth and frosty. Pour into a big glass cup, bowl or milkshake glass and top with whipped cream and chocolate savings.