Special-Occasion Brownie Dessert
["4 (1 oz.) sq. unsweetened chocolate", "1 c. butter or margarine", "1 1/2 c. sugar", "4 eggs, beaten", "2 tsp. vanilla extract", "1 c. all-purpose flour", "1/4 tsp. salt", "1 c. chopped walnuts", "Graham Cracker Crust (recipe follows)", "2 c. frozen whipped topping, thawed", "finely chopped walnuts (optional)"]
["Combine chocolate and butter in a heavy saucepan.", "Place over low heat, stirring constantly, until melted.", "Add sugar, stirring until combined.", "Remove from heat and cool 5 minutes.", "Stir in the eggs and vanilla.", "Combine flour and salt; add to creamed mixture, stirring well.", "Stir in 1 cup walnuts."]
["unsweetened chocolate", "butter", "sugar", "eggs", "vanilla extract", "flour", "salt", "walnuts", "Graham Cracker Crust", "frozen whipped topping", "walnuts"]