In a medium-sized mixing bowl, combine equal parts of instant coffee, sugar, and hot water. For example, if you're using 2 tablespoons of instant coffee, use 2 tablespoons of sugar and 2 tablespoons of hot water.
Using an electric hand mixer or a whisk, vigorously whisk the mixture together until it becomes frothy and thick. This process can take anywhere from 2 to 5 minutes, depending on your desired consistency. If using an electric hand mixer, start at a low speed and gradually increase the speed as the mixture thickens.
Once the mixture has reached a thick and creamy consistency, it is ready to be spooned over your choice of milk or iced coffee. Fill a glass with milk or iced coffee, leaving some room at the top for the whipped coffee mixture.
Spoon the whipped coffee over the milk or iced coffee, creating a layered effect. You can use a spoon to gently swirl the whipped coffee into the milk or iced coffee for a marbled effect, or you can let it sit on top for a more dramatic presentation.
Grab a straw or a spoon and give your Dalgona coffee a quick stir before enjoying it. This will help to mix the flavors and ensure that each sip is perfectly balanced.