A very good ginger cake

Susie brought us this wonderful ginger cake at the weekend. The recipe came from the BBC Olive magazine site. She says it's a bit of a faff to make, but it's definitely worth it, lots of subtle flavour - dark muscovado notes. She made it in one of those rubbery moulds I'm always too mean to buy, which is why it bulges with voluptuous Ruben-esque curves ...