I know rainbow cakes have become quite popular, particularly after the Great British Bake Off did their episode on surprise cakes and there are tons of recipes for them on the Internet, however I still thought I'd share this. I first came across a rainbow cake at a meeting of the Clandestine Cake Club at Ms Marmite Lovers in London. MsMarmite had brought it along as her creation. They tend to look unassuming from the outside - plain white buttercream, which I guess makes the novelty of the rainbow of colours inside even more appealing.
I've never made one as I'm not keen on using lots of food colouring, but I have to say the final result looks amazing!
I don't have any photos of the step by step but my sister used this Mary Berry recipe for the cake and this recipe without the addition of white chocolate for the buttercream. The buttercream and piped on the outside in a rose pattern like in this and this cake.
I have seen varying degrees of success with rainbow cakes on the internet so i asked her to share her tips with me and they are as follows:
- make at least a 6oz mixture for EACH layer
- use good quality gel or powder food colouring. I prefer gel.
- unfortunately natural food colourings are probably a no go as they don't tend to be as deep in colour.
- add the food colouring a very small amount at a time, mixing well between additions to make sure you don't overdo the colours. My mum says 'you can always add more but you can't take it out'
- once the cakes are baked use a cake leveller to remove the top of each cake and ensure they are the same height (make sure you don't move the wire on the cake cutter between cutting each cake!
- put quite thick layers of butter cream between each layer to ensure there are clear divisions.
- decorate the cake quite plainly.
- use a better knife than this to cut it if you want really clean layers! She was at work and hence didnt have a great knife.