Total Calories: 1,550
Cream butter or margarine, brown sugar and granulated sugar together, beating well. Add egg yolks, continuing to beat. Sift together flour, baking powder and soda add to creamed mixture. Evenly spread into a well-greased 17 x 11-inch jelly roll pan. Sprinkle chocolate bits and nuts over mixture. Beat egg whites with cream of tartar when soft peaks form, start adding confectioners' sugar a tablespoon at a time, beating well after each addition. Spread this over the batter in an even layer. Bake in a preheated 325° F oven for 35 minutes or until lightly browned. Remove from oven and score into 1 1/2 -inch squares while still warm. Cut into squares when cold.