1Grease bottom and sides of 8- or 9-inch square glass baking dish with butter. Spread nuts in pan. Heat remaining ingredients to boiling in heavy 3-quart saucepan over medium heat, stirring constantly.
2Cook over medium heat about 35 minutes, stirring frequently, to 245°F on candy thermometer or until small amount of mixture dropped into cup of very cold water forms a firm ball that holds its shape until pressed. Immediately spread over nuts in pan. Cool completely, about 2 hours.
3Cut candy into 1-inch squares. Wrap individually in waxed paper or plastic wrap. (Use metallic plastic wrap for a candy shop finish.) Store wrapped candies in airtight container.