Combine sugar and instant coffee in a bowl and pour in boiling water. Whip until the mixture is thickened and holds its shape, 3 to 4 minutes
Pour 1/2 of the milk into an old fashioned glass.
Fill a cocktail shaker with ice and pour in remaining milk, amaretto, and creme de cacao. Cover and shake vigorously for about 2 minutes. Strain into the old fashioned glass. Spoon the dalgona whip on top.