When we lived in New Mexico, one of the Observers (people that run the telescope) at APO used to make this very rich and evil hot chocolate for us.
Equipment:
Medium saucepan
large whisk
square metal spatula (the kind used to flip hamburgers)
Ingredients (rough guesses, fiddle until it tastes right):
8 oz sweetened consensed milk. (I can't seem to find it in smaller
quantities than 14 oz, though.)
11.5 oz bag bittersweet (or unsweetened) chocolate chips
GET GOOD CHOCOLATE.
I usually use Ghiradelli "double chocolate" chips
If all you can get is Hershey's, don't bother
1/3 gallon whole milk
1 Tbs allspice
6 oz honey
Instructions:
Pour about 8oz sweetened condensed milk into saucepan over medium heat. Stir it with the spatula until just before boiling. You can tell when it is about to boil because the the viscosity drops. Once the sweetened condensed milk is hot, add the chocolate chips and continue stirring. Be careful not to let the melting chocolate burn onto the bottom of the pot! When there is no more sweetened condensed milk left, and what you have is lumpy chocolate glop, begin adding whole milk, a few cups at a time. Stir continuously until you have a uniform liquid. You will probably want to alternate between the spatula and whisk as stirring instruments. The spatula will help you get stuff out of the corners of the pot and off the bottom, while the whisk is much better for getting the chocolate glop to dissolve into the milk faster.
Once you have a uniform liquid, add milk, allspice, and honey to taste. (Do not add so much milk at once that the pot becomes cool, because the chocolate can start condensing.) The quantities listed in the ingredients list are my rough estimates of how much I usually use.
Commentary:
The more sweetened condensed milk you start with, the easier it is to melt the chocolate without burning it. I like the flavor of the honey, though, and so use as little sweetened condensed milk as possible so I can add more honey without it being way to sweet. If you are feeling adventurous, you can use evoporated milk instead of sweetened condensed milk, but it makes keeping the chocolate from burning harder.
If you cut back on how much milk you use, this becomes a recipe for an ice-cream topping. You can experiment with replacing the allspice with cinnamon or chili powder. Different types of honey will produce different amounts of "burn." Do not try sweetening with maple syrup instead of honey.