Cream one-half cup of butter, add gradually one cup of fine granulated sugar. After adding the last of the sugar, add two eggs, yolks and whites beaten together and give a very vigorous beating. Now add alternately, a little at a time, one-half cup of water and one and one-half cups of sifted pastry flour having added two level teaspoons of baking powder and about one-fourth teaspoonful of nutmeg to the latter. Add one-half teaspoonful of vanilla. Place one-third of this batter in a separate bowl and add to it one-half ounce of unsweetened chocolate melted, or one level tablespoonful of cocoa. Mix thoroughly. Now put a thin layer of the yellow batter into a long, narrow bread pan (about 4 x 9), then brown and yellow in streaks until all is used. Bake one hour in a slow oven.