Can I make the Chocolate Guinness Cake in advance? A week earlier?
Nigella's Chocolate Guinness Cake (from FEAST) is a very moist cake that does keep well but is at its best up to 5 days after baking. You can store the un-iced cake in an airtight container, or by wrapping it tightly in a layer of clingfilm, preferably in a cool place. The cake should be iced just before serving and after it has been iced then the cake is best kept in the fridge, particularly in warm weather, as the icing is more perishable.
For longer periods we would recommend freezing the un-iced cake. Wrap it in a double layer of clingfilm and a layer of foil and freeze for up to 3 months. To thaw the cake unwrap it and put it on a wire rack at room temperature for about 4 hours. Ice the cake just before serving and eat within 5 days.