Combine sugar, butter and milk in a 2-quart glass mixing bowl. Cook on roast (70%) for 2 to 3 minutes, or until mixture begins to boil. Remove from oven and stir well. Cook on roast for 2 to 3 minutes, or until mixture boils and sugar is COMPLETELY dissolved. Stir in marshmallows (10 miniture marshmallows equal 1 [ONE] large marshmallow) and chocolate chips and beat until smooth. Fudge sets up rapidly, so don't delay when doing this step. Stir in nuts and vanilla and spread mixture into a 8 inch buttered baking dish. Cool. Cut into 1 inch squares. Dennis Spivey, Prodigy Food & Wine Board