PLACE CHOCOLATE, BRANDY and vanilla in the top of a double boiler filled with boiling water, place over medium heat and cook until chocolate is melted. Remove from heat, but leave melted chocolate in the double boiler. Add the yolks and mix until incorporated. Meanwhile, place milk in a small pot over medium heat and scald it. Immediately remove from heat and slowly pour over the melted chocolate, stirring constantly. Pour into mugs and serve immediately.