Like the fresh watermelon from the vine, this old recipe from 1890, (The Model Cookbook), has a pink interior with ‘seeds’ made up of raisins. The cake is flavored with rose water, a flavoring not used much today but would be a lovely touch for a light, summertime cake.
Water Melon Cake
Take one-half cup of white sugar, whites of four fresh eggs, half a cup of sour milk, half a cup of butter, two cups of flour; cream the butter and sugar, then add the milk with not quite a half teaspoonful of soda; stir in the flour, then a little egg, and so on, till all the ingredients are added. The eggs must be beaten till very light. This completes half the recipe. Then take one and one-half cups of pink sugar, one-half cup of butter, one-half cup of sour milk, not quite half a teaspoonful of soda, and two cups of flour; flavor the pink with anything you wish. Rose water is much used. Seed a quarter of a pound of raisins; rub them well in flour. After both kinds are ready, spread well the bottom and side of your pan with white dough; fill up with pink, leaving enough white to cover the top.