EXECUTIVE SUMMARY: stir 1 teaspoonful of cocoa powder and 2 teaspoonsful of sugar into a mug, add a tablespoon full of milk and stir until smooth, fill with milk, stir well, and microwave until it is hot.
Some of the folks at our house think there's something special about Papa's hot cocoa and therefore it is suitable for offering as a gift. So here is how I make my favorite hot cocoa.
First, you should understand that I'm not a food snob, nor even a cocoa snob. I'll tell you what I like and why, and suggest that you experiment a bit to find what you like. I can't promise you that this recipe will give you the perfect cup of cocoa the first time you try it. It will give a reasonable place to start. It is simple, using few ingredients, few utensils, and no mysterious, complex cooking methods. It is not as quick as dumping a packet of mix into a mug and adding hot water, but the results are worth the bit of extra time and effort -- at least in my estimation.
This recipe is designed for brewing one mug of cocoa; if you want more than that -- say, to delight a friend with -- you can prepare two mugs separately and microwave for a longer time. or you could make even more (to make more friends) and resort to cooking the whole batch all at once in a saucepan on the stovetop.
Measure the cocoa powder and the sugar into your mug. The measurements don't have to be precise, don't be afraid to adjust them to suit your taste. If you prefer a strong cocoa flavor use a little more cocoa powder; if you want it less sweet use a little less sugar.
Stir. The cocoa powder will likely form some clumps when it is placed in the mug. Stir your cocoa+sugar mixture until these clumps are mostly gone and the powder has a uniform texture and color. This is why I like a mug with rounded sides: it is easier to get rid of these clumps when you can press the back of the spoon against the side of the mug to squash those clumps, and that is easier if the mug doesn't have a corner where the sides meet the bottom.
Add a splash of milk, one tablespoon full or so is enough. Stir. Stir some more. Keep stirring. It is this step that I find makes the most difference in my satisfaction with the end product. I don't like there to be a gritty, chalky, or powdery sensation when I sip my cocoa. You want to stir this mixture until it is smooth and glossy looking. If it looks lumpy or chalky, keep stirring. When you're done stirring it should look a lot like chocolate syrup -- in fact you could probably drizzle this over your ice cream or cream puffs or cupcakes or other dessert and be quite happy with the taste. The reason I only add a little milk at this stage is that I'm less likely to slosh some of this precious-but-messy goo out of the mug onto my shirt or some other place I'd have to clean up (and it's much easier to stir out the lumps with only a tiny portion of milk).
Keep stirring as you add enough milk to fill your mug. Now, don't get crazy with the "fill" part -- leave enough space at the top of the mug so you can carry it to the microwave and back without spilling it all over. More importantly, as the milk gets hot it tends to froth up and you don't want it to overflow and make the outside of your mug all messy.
Stir again. No, I'm not crazy, just a little obsessive-compulsive. Actually, the stirring is a part of the Hot Cocoa Experience, much like smokers have certain rituals associated with their habit: a certain way of removing a cigarette from the pack, how it is lit, the way it is held -- all of these become an expected, comfortable (and comforting) part of the routine. This last stirring just before you close it into the microwave is a superstitious part of that routine.
Microwave for exactly one minute and forty seconds (1:40). This is because microwave ovens are just dumb machines, and they don't have an "About" button; so to keep you from confusing your dumb machine I won't tell you to cook your cocoa for about 1:40, I'll say cook for exactly 1:40. That means you have to be the smart one and watch it cook. If it begins to boil over, or smoke, or turn green-and-purple, you'll have to rescue it from the microwave because it's too dumb to figure any of that out. You'll know your cocoa is ready when it begins to get foamy or frothy on top and it looks like it might boil over soon. If you've been paying attention you've probably figured out you might have to adjust the cooking time because your mug is bigger or smaller than mine, your milk was warmer or colder than mine, your microwave has more or less power than mine, or because it is Tuesday and I made my cocoa on Friday.
Stir again, if you want to.
Enjoy! Yes, that's one of the rules of the Hot Cocoa Experience. Sip daintily at first to savor that wonderful flavor and aroma, and because it is still hot; then later you may slurp down big gulps so you get it all while it is still warm. The younger folks at our house think that hot cocoa is perfect for dunking their cookies into, but I'm far too refined to condone such undignified behavior. Oh yes, we often enjoy cookies with our cocoa, especially when the cocoa-and-cookies snack serves as the intermission of our story time. Little girls sometimes try to pretend they're having an elegant tea party, but you can obviously see that cocoa demands a sizeable, hefty mug and is a suitable elixir for any super-hero.
Here's a few of the accessories and add-ons you might consider for your mug of cocoa:
http://www.himonkey.net/cooking/cocoa/index.html offers some illustrated guidance for folks who would rather read picture books.
http://www.streetdirectory.com/food_editorials/snacks/chocolates/hot_cocoa_mix_recipe_4_tips_2_recipes.html has more (or at least, different) details to bore you with (and they're nearly as opinionated as mine).
http://whatscookingamerica.net/Beverage/HotChocolate.htm offers even more information, but these folks are getting awfully close to being hot cocoa snobs.