Melt chocolate in top of double boiler over hot water. When melted, add sweetened condensed milk; stir, add vinegar, flavoring and nuts. Stir to blend. Pour into parchment-lined, 9-inch square pan. Smooth and chill about 2 hours. Turn onto cutting board, peel off paper and cut into squares. Refrigerate in tightly covered container.

Hazelnut Industry and The Hazelnut Marketing Board