Old Fashioned Penuche

Grease 8" by 8" metal baking pan. Line bottom and sides of pan with foil, allowing foil to extend above pan on 2 sides, grease foil. In heavy 4-quart saucepan, melt butter over medium heat. Add cream, granulated sugar, brown sugar, and corn syrup, heat to boiling over high heat, stirring frequently, until sugar completely dissolves. With pastry brush dipped in water, wash down sugar crystals on side of pan. Set candy thermometer in place and continue cooking, without stirring, until thermometer reaches 238F., or soft-ball stage (when small amount of mixture dropped into very cold water forms a soft ball that flattens on removal from water). Remove saucepan from heat. Cool mixture to 210F., about 8 minutes, without stirring. Sprinkle white chocolate over mixture, let stand 1 minute. Add walnuts and stir with wooden spoon just until chocolate and nuts are incorporated (do not over mix). Immediately pour mixture into pan (do not scrape inside of saucepan). Cool candy in pan on wire rack 30 minutes or until firm, but still warm. Lift foil and candy out of pan and place on cutting board. While warm, cut candy into 8 strips, then cut each strip crosswise into 8 pieces. Cool completely on foil on wire rack. Store at room temperature in tightly covered container, with waxed paper layers, up to 3 weeks. Makes about 21/4 pounds or 64 candies.