Melt chocolate pieces and butter over hot (not boiling) water. Beat eggs until light and fluffy; gradually beat in sugar. Stir in oats, baking powder, salt, vanilla, walnuts and chocolate pieces.

Pour batter into greased 8-inch square baking pan. Bake in preheated moderate oven (350 F.) 30 to 35 minutes. Cool; cut in squares. Sprinkle with confectioners' sugar, if desired.

Reprinted with permission from The Quaker Oats Company Electronic format courtesy of Karen Mintzias