Melt chocolate, peanut butter and butter. In a large bowl beat eggs, sugar, salt and vanilla. Add melted chocolate mixture. Add flour gradually. Mix well. Add the nuts. Pour into a greased 13x9x2-inch greased pan. Bake at 180ºC . for 45 minutes to 50 minutes. Let cool, cut into squares. From ; the Ultimate Peanut Butter Cookbook by Arthur Boze