Surprise Bars
["1 oz. unsweetened chocolate", "1/2 c. graham cracker crumbs", "2 Tbsp. margarine, melted", "1/2 c. butter or margarine", "1/2 tsp. vanilla", "1 egg", "1/8 tsp. baking soda", "1/8 tsp. salt", "3/4 c. walnuts, chopped", "1/2 c. sugar", "3/4 c. all-purpose flour", "1/4 c. dairy sour cream"]
["Melt chocolate and set aside to cool.", "Blend crumbs and 2 tablespoons melted butter; set aside.", "Cream the 1/2 cup butter with the vanilla extract.", "Add sugar gradually, beating until fluffy.", "Add egg and beat thoroughly.", "Sift flour, baking soda and salt together.", "Add alternately to creamed mixture with the sour cream, mixing until blended after each addition."]
["unsweetened chocolate", "graham cracker crumbs", "margarine", "butter", "vanilla", "egg", "baking soda", "salt", "walnuts", "sugar", "all-purpose", "sour cream"]