Caramels

1. Line an 8x8x2-inch or 9x9x2-inch baking pan with foil, extending foil over edges of pan. Generously butter the foil. If desired, sprinkle walnuts over bottom of pan. Set pan aside.

2. In a 3-quart heavy saucepan, melt butter over low heat. Add brown sugar, half-and-half, and corn syrup; mix well. Cook and stir over medium-high heat until mixture boils. Clip a candy thermometer to the side of the pan. Reduce heat to medium; continue boiling at a moderate, steady rate, stirring frequently, until the thermometer registers 248 degrees F, firm-ball stage (45 to 60 minutes). (Adjust heat as necessary to maintain a steady boil and watch temperature carefully during the last 10 to 15 minutes of cooking as temperature can increase quickly at the end.)

3. Remove saucepan from heat; remove thermometer. Stir in vanilla. Quickly pour mixture into prepared pan. Let stand about 2 hours or until firm. When firm, use foil to lift it out of pan. Use a buttered knife to cut into 1-inch squares. Wrap each piece in waxed paper or plastic wrap. Store at room temperature.