Line an 8-inch square
pan with a strip of foil or parchment. Measure first six ingredients
in order listed into a 2 to 2-1/2 quart saucepan. Bring to
full boil over moderate heat, stirring constantly. Boil exactly
5 minutes, stirring constantly. Remove from heat, add chocolate,
stirring quickly until melted. Stir in vanilla and nuts. Turn
into prepared pan. Let stand in cool place or refrigerator
until firm. Cut into squares. Makes about 2-3/4 pounds.