For one huge mug or two small mugs, fill said mugs with milk and pour into a pan. Turn heat to medium high. Add one really heaping spoonful of straight cocoa powder, and two heaping spoonfuls of brown sugar and a little splash of vanilla. whisk with a whisk, and keep an eye on it until it starts to show signs of doneness, which is steam rising off the surface, about 5 minutes. Don't let it boil or you will burn your tongue on it. Pour into the mugs and enjoy! Of course it is also excellent with fresh whipped cream and you can add cinnamon or mint if you like though I'm a purist and prefer it without. I've also tried making it with bars of fancy chocolate and while it is nice, I prefer the cocoa powder method. Serve with a pot of honey, so those who like it sweeter can sweeten to taste.
For my near-perfect ice cream sauce, use the same proportions of sugar and cocoa and vanilla, but use much less milk, just enough to make a thin sauce. let simmer two minutes on the stove and pour over waiting bowls of vanilla bean ice cream. If you have any in the cupboard, a splash of rum is good in this too, though not necessary.