Specifically Nigella's Old Fashioned Chocolate Cake - p269 of Feast. It involves sour cream but is basically just a rich sponge - would that work OK for cupcakes? Lower oven temperature (than 180) needed? What about using a brownie recipe for cupcakes? Am I missing something blindingly obvious? This is all part of my over-the-top plan for DD's imminent 18th birthday celebrations. Thanks.