1/2 stick butter
1 lb. light brown sugar
3/4 c. heavy cream
1 tsp. vanilla
1/2 - 7 1/2 oz. jar marshmallow fluff

Do not substitute any ingredients! Place sugar, cream and butter in saucepan and let all melt slowly. Cook until it reaches 240 degrees on candy thermometer. Remove from heat, add vanilla and fluff. Beat until it starts to thicken (about 6 minutes). Add walnuts and pour into an 8 x 8 inch buttered pan.