Vanilla and Chocolate Marble Cake

To all intents and purpose this is a Chocolate Swirl Cake (see Chocolate Squirrel Cake post of last year). Sounds a bit posher maybe but a Chocolate Swirl cake it is.
My friend sent me a link to a new website last week, My Kitchen Table, that has some great chefs on there showcasing new recipes. Having had a little surf and feeling very baking deprived after my January of non-baking I decided to make a cake and chose Mary Berry's above mentioned Marble Cake.
As you will see from the recipe it is an all in one cake, all the ingredients go in together and you mix with an electric whisk until all combined. Then it's a matter of halving the mixture and adding you chocolate (in the guise of cocoa powder) to one half. Then you have the fun of putting them into the loaf tin in a higgledy piggledy sort of way (technical term) and that way you get your marbling.
I followed the oven instructions and took off the 20 degrees for a fan oven but after 40 minutes it was still rather soggy so for the last ten minutes I put it up to 160 and it was perfect. Nicely risen and springy to the touch.
The icing was my favourite bit, a whole new way of making icing. You melt the butter and then add the cocoa powder (over the heat) and stir until smooth. Add the icing sugar with a couple of tablespoons of milk and stir until it's all incorporated then take off the heat and mix until smooth. You get a beautiful glossy icing and it hardened very quickly. I then added it to the loaf and voila. I didn't have any white chocolate so the final flourish didn't happen but I think that's ok.
I brought the cake into work last Monday and we had it in the afternoon as everyone was flagging. It got good reviews and lots of nostalgic comments about their mothers making it when they were growing up. I love that about cakes, they never go out of fashion.