Whipped Coffee Mousse (in 5 Minutes)

1 Add the instant coffee, sugar, and hot water to a food processor or high-speed blender.
2 Blend until the mixture becomes thick, pale, and fluffy.
3 Add the ice and blend briefly until cold and mousse-like.
4 Add cold water 1 tablespoon at a time only if needed to reach the consistency you want.
5 Spoon into a glass and dust with cacao powder.