This section is from the book "The Young Housekeeper's Friend", by M. H. Cornelius. Also available from Amazon: The Young Housekeeper's Friend.
One cup and a half of white sugar, half a cup of butter, half a teaspoonful of soda dissolved in half a cup of milk, three cups of flour, with one teaspoonful of cream-of-tartar stirred into it, and three eggs beaten thoroughly, yolks and whites together. Flavor with essence of lemon. Bake in three square pans.
For the filling, use one cup of milk, half a cake of the sweet chocolate grated, and two eggs.
Boil the milk, with the chocolate in it, for two or three minutes. Stir it often, and add the beaten eggs. Spread the chocolate between the sheets, like jelly-cake, or cut the sheets into square pieces of the right size for the table; split each one, and put the chocolate between the two parts. If the chocolate runs, add more to make it thicker.
Bub to a cream one cup of sugar and half a cup of butter. Add the whites of two eggs beaten stiff, then a cup and a half of flour, with one teaspoonful of cream-of-tartar. Dissolve half-a teaspoonful of soda in half a cup of sweet milk, and stir in to the cake well. Flavor with essence of lemon. Bake in one loaf. When cold, cut in four or five layers, with a very sharp knife. They should be about half an inch thick.
For the frosting, beat stiff the whites of two eggs, and stir into them one cake of "German sweet chocolate," grated. Add powdered sugar, but not enough to make the mixture too stiff. It should not be so soft as to run. If it becomes too thick, put in two or three teaspoonfuls of cold water. Spread the frosting thus prepared between the layers, and over the top also, if you wish.
 
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