From 1912:

One and a half cups of sugar, half a cup of butter, and the same of sweet milk, two cups of flour, three eggs, the yolks and whites beaten together; one teaspoonful of soda dissolved in milk, half a cup of grated chocolate dissolved in half a cup of milk and stirred until it thickens. Stir in milk and soda at the last. Flavor with vanilla.
This is for a three layer cake. I use a coffee cup for measuring.

One cup of white sugar, two-thirds of a cup of milk, butter the size of an egg.
Boil these ingredients together until the mixture drops from the spoon like jelly.
Spread between the layers and on top.
The cake, when baked, is almost mahogany color and very good.