In a glass, mix boiling water, instant coffee granules, and sugar. Stir until the sugar dissolves. Let it cool in the refrigerator for a couple of minutes.
Add ice cubes, pour in the milk, give it a good stir, and enjoy!
Notes
Coffee: If you like using grounds or beans for your coffee, you can make it using your favorite way of brewing. Follow the package directions, but double the number of beans to make the coffee more concentrated because the ice will slightly dilute it.