Butter the inside of a saucepan. Put in two ounces of unsweetened
chocolate and melt over hot water. Add two cups of light brown sugar and
mix well. Add one ounce of butter and half a cup of rich milk. Cook
until mixture forms a soft ball when tested in cold water. Flavor with
vanilla and pour, while hot, over each service of the roll. It
immediately hardens, forming a delicious caramel covering to the ice
cream.