I found a recipe on Allrecipes but changed it a bit, to suit my tastes. This is a nice, rich cocoa that will warm your hands on a cold almost-winter's day.
1/3 cup cocoa
1/2 cup sugar
1/8 tsp salt
1/3 cup boiling water
3 1/2 cups milk
Vanilla extract (or some other flavour)
Combine cocoa, sugar and salt in a large saucepan. Add boiling water and heat over medium heat until bubbles begin to form, continuously stirring with a whisk. Add milk and continuing heating and stirring until it is hot. Do not let the milk boil. Remove from heat. Add a dash of your favourite extract (vanilla, almond, mint, hazelnut, coconut) to give it extra flavour. Enjoy on its own or with a crisp shortbread (or, I suppose, another delectable treat would suffice.)