Such a season of birthdays! Everyone seems to be having one at the moment, and for those seeking a special cake to take along for a celebration, may I heartily recommend Nigella Lawson's chocolate fudge cake (in either the cups or grams incarnation)? I was happy to have halved the sugar recommended for the icing; and can I share with you the delight of trickling freezer-chilled water into oil and melted butter? The fats seized up and became so white and fluffy, it was quite the pleasure of science in action.