Cream two-thirds cup of butter with two cups of granulated sugar; add
one-half cup of milk, yolks of four eggs, one cup of hot mashed
potatoes, one cup of chocolate, one teaspoon each of cinnamon, cloves,
and nutmeg, one teaspoon of vanilla, one cup of chopped walnuts, two
cups of flour, two teaspoons of baking-powder, then beaten whites of
four eggs. Bake slowly in two pans, and cut in half when cold. Put jam
between layers.