Magic Chocolate Crackle Bars
["1 1/2 c. all-purpose flour", "1/2 c. sugar", "1 tsp. baking powder", "1/2 tsp. salt", "2 eggs, separated", "1/4 c. shortening, butter or margarine", "1 (1 oz.) unsweetened chocolate, melted", "1 c. sugar", "1 c. chopped nuts", "1 tsp. vanilla", "1 (1 oz.) unsweetened chocolate, melted (in addition to one above)"]
["Preheat oven to 325\u00b0. Grease 11 x 7 x 2-inch baking pan (or square one); set aside. In medium bowl, combine flour with 1/2 cup sugar, baking powder and salt. Add egg yolks; mix well. Cut in shortening and 1 ounce chocolate until crumbly. Firmly press into greased pan. Bake at 325\u00b0 for 5 to 7 minutes."]
["flour", "sugar", "baking powder", "salt", "eggs", "shortening", "unsweetened chocolate", "sugar", "nuts", "vanilla", "unsweetened chocolate"]