In a small mixing bowl, add 2 tablespoons each of instant coffee, sugar, and boiling water.
Using a handheld electric mixer, beat the mixture on medium-low speed until it becomes thick and fluffy, like whipped cream. Scrape down the sides of the bowl with a spatula and keep mixing.
Taste the whipped coffee base. If you’d like it sweeter, add the optional third tablespoon of sugar. Continue whipping until the mixture is pale golden brown, light, and airy. This usually takes 3–5 minutes.
Pour 8 ounces of milk into a glass. For hot coffee, warm the milk first. For iced coffee, fill the glass with ice cubes before adding the milk.
Spoon the whipped coffee mixture on top of the milk. Stir well with a straw or spoon, or sip both layers together.
Optional: Sprinkling cinnamon or cocoa powder on top for extra flavor.