Heat 1/2 cup whipping cream and chocolate in a heavy saucepan over low heat, stirring constantly, until chocolate melts and mixture is smooth. Cool slightly,  Pour mixture evenly into 6 6-ounce individual baking dishes, set aside.

Whisk together remaining 2 cups whipping cream, yolks, 1/2 cups sugar, and vanilla until sugar dissolves and mixture is smooth.  Pour evenly into prepared baking dishes.  Place dishes in a 13x9 baking dish; add hot water to large dish to a depth of 1/2 inch.

Bake at 275 for 1 hour and 1 minutes or until almost set.  Center will be soft.

Cool custards in water in pan on a wire rack.  Remove custards from pan and cover and chill for at least 8 hours.

Sprinkle 1 tablespoon brown sugar over each custard, place custards in baking pan.

Broil 5-1/2 inchs from heat until sugar melts.  Let stand 5 minutes to allow sugar to harden.

Note: Make the custard a day ahead and torch the topping at the last minute.