DS wants one of those rainbow coloured layered sponge cakes for his birthday

[FakePlasticLobsters]

Can anyone recommend a good recipe for one?

I've made a chocolate sponge before but these seem a bit ambitious. And what's the best kind of colouring and flavouring for the rainbow?

sorry, this one.

Dr oetkers aren't strong enough for the really vibrant colours, they turn out more pastel in shade. I would try another brand like Wilton you can buy them online but I've never tried them, I used oetkers and they just weren't bright enough.

Marking place for later......

I've only manage to get bright colours like in the pictures by using a cake mix (which practically destroyed my baker's soul). I found normal mixture was too yellow-y and the colours were sludgy, even with gel colours.

Hope the cake goes well.

This thread has brought some lovely memories of my mum back to me. Marble birthday cakes were her speciality when we were little. She died last summer aged 83 and it is really nice to remember the stuff she did :). Cutting edge woman that she was!

I made one for my dd's birthday. It was a bit of a faff to do but not difficult and it was a really good surprise when we cut the cake and I have to say it looked fab!

I found this blog online and copied it, yes to using gel dyes, and also I used 6 foil tins for the 6 layers and cooked in 2 batches. For the icing in between the layers I alternated between jam and the frosting for the outside.

kerrycooks.wordpress.com/2012/04/02/rainbow-cake/

Go for it!!

Yes I made one last year for dd's 6th birthday. You will need plenty of food colourings. More than you think that you need, as the colours are not that vibrant once baked....
I made mine over a few weeks - freezing a couple of layers at a time, as the colours were not quite right!!!! So please give yourself plenty of time to bake the separate layers.
But it looked fab once made and everyone loved it! The pic is obviously as a slice, will try and load the full pic...

If not, try a confetti cake. Just fold bright sugar strands that you normally sprinkle over cakes into cake mixture just before you put it in the tins. The strands melt so they ate not crunchy but they leave behind loads of dots of color, really easy

I like this kit kat and M&M one (or you could use skittles)

http://micakela.wordpress.com/2012/07/24/kit-kat-and-mm-rainbow-cake-15/

The latest edition of Good Food magazine has the rainbow cake as its cover with all info on how to get a professional result inside. Mine's a subscriber copy so prob not in shops till tues/wed.

I did one last month for dd1. I used Wilton paste colours, got them in Hobbycraft.

I love the idea of confetti cake. Must try that. Am doing a cake for dd1`s birthday party tomorrow.

I've done a confetti cake, they are fab. Also made confetti fairy cakes at Christmas with tiny red and green Christmas trees baked into them.

My dds both want a rainbow cake for their birthdays in May so these tips are great.

I'm going to try one of these later in the week, I've got some little pots of gel colour from Asda but I can't remember what brand they are - did people use normal buttercream icing as frosting or something different?

When people have said use a lot of the colouring - how much is that per cake, a table spoon? More? Not sure what I'll use the colours for again so I'm not bothered it I need to chuck loads in!!