A very pleasant beverage in its own right, chocolate milk lacks the intensity you'd find in a good cup of hot cocoa. For chocolate lovers in hot climates, the obvious answer is to make cold cocoa instead. It provides the same chocolate kick as a cup of cocoa, but in an icy-cold, summer-friendly form.
The cold-mix method is the simplest way to make cold cocoa.
In a mixing bowl or large measuring cup, combine 6 to 8 tablespoons of cocoa powder with 4 tablespoons of sugar.
Stir in cold milk, one tablespoon at a time, until it makes a thick paste. Gradually add milk to the paste, thinning it, until you've incorporated a full quart.
Whisk the milk thoroughly -- or better yet, zap it for 20 seconds with a blender or "stick" blender -- and then refrigerate it. The cold cocoa has a smoother texture after a day in the fridge, so make it up ahead of time whenever possible.
For a single cup, start with just 1 to 2 tablespoons of cocoa and 1 tablespoon of sugar and then follow the same steps.
The hot-mix method calls for making regular hot cocoa, then refrigerating it. The steps are identical, except you heat or "scald" your milk almost to the boiling point, before you add it to the cocoa-and-sugar mixture. Once you've added enough milk to make a thick paste, stir the paste into the hot milk until well blended. Cool the hot cocoa, then pour it into a pitcher or milk bottle for storage. The cocoa will have a smoother texture than cold-mixed cocoa.
Starting with hot cocoa, and resting cold-mix cocoa overnight in the refrigerator, have two things in common: They both improve the beverage; and they both make you wait. If you like the idea of having excellent cold cocoa whenever you want it, your best option might be a scratch-made chocolate syrup.
Use roughly the same proportions of sugar and cocoa, but double them. In a saucepan, whisk the cocoa mixture into a cup of boiling water with a pinch -- 1/8 to 1/4 teaspoon -- of salt. Simmer the mixture for 3 to 5 minutes, stirring, until it comes together smoothly and starts to thicken. It'll keep thickening as it cools, so don't worry if it seems a bit thin at first. Stir in a teaspoon or so of vanilla, if you wish, once you've taken the saucepan off the heat.
A batch this size makes enough syrup for three to five glasses of cold cocoa, depending on the size of the glass and the intensity of your chocolate addiction.
Tips
If you have special dietary needs in your home, the sugar can be replaced with any other natural or artificial sweetener, and the milk with your choice of non-dairy rice, nut or soy milk. If you opt for a liquid sweetener, stir it into the milk rather than the cocoa powder.