In a medium bowl, combine the instant coffee, sugar, and hot water.
Using a whisk or an electric mixer, whip the mixture until it becomes thick, frothy, and light brown. This can take about 3-5 minutes with an electric mixer, or longer by hand.
Fill your serving glasses with milk and ice cubes if desired.
Spoon the whipped coffee mixture on top of the milk.
Serve immediately and enjoy your Dalgona coffee!
Notes
Adjust the amount of sugar to your liking. For a stronger coffee flavor, use more instant coffee.