The recipe was just sitting there, minding its own business, in her book "Feast." Just about exactly the same as the original recipe, which is well-loved on this board (do a search for it and see), with the addition of 1/2 cup of cocoa and some leavening. I upped the cocoa just a little bit (1/3 cup rather than 1/4 cup for a half-recipe). It is dynamite! Comes out wet and black as night and slices cleanly, with the bitterness of the citrus rind singing harmony with the almost tannic quality of the Valrhona cocoa. Less sweet and cloying than the original, and even the texture was improved by the cocoa. This is a very close approximation of my childhood favorite ice cream, Baskin-Robbins Mandarin Chocolate Sherbet, in cake form. Let me know what you think!