To make coffee decoction, heat ¼ cup water in a non-stick pan, add coffee powder and mix well. Cook till it thickens. Cool to room temperature.
Blend together chocolate ice cream, chocolate sauce reserving some for rimming and coffee decoction till smooth.
Rim individual glasses with reserved chocolate sauce, place some of the ice cubes in each glass, pour the prepared chocolate cooler, pipe out a rosette on top, dust coffee powder on top and serve chilled.