Boil some hot water in a tea kettle or in a small saucepan. In a large mixing bowl or stand mixer, add the instant coffee, sugar, and hot water. Whisk until the color becomes light and the texture is frothy—about 5 minutes. This will much easier for you if you use an electric mixer. Once the coffee is frothy, add in your flavoring. Whisk for another 15 seconds or so. Remove the electric mixer and mix the rest with a spatula, until everything is combined. Scoop the whipped coffee on top of milk. Top with any desired toppings, like extra chocolate or caramel sauce. Mix and enjoy.