Yikes.

Saw it and instantly thought about my son's upcoming bday. Will try; probably with just two or three colors, though.

Very fun.
I've posted this link on Ohdeedoh before, but I just can't resist doing it again. I made a rainbow layer cake for my daughter's rainbow-theme birthday party. It was an idea I found on the Web somewhere. You just make several layers, each a different color of the rainbow, stack them up with frosting in between, and then cover the whole thing in white frosting (like a cloud).
Pictures here:
http://pennycarnival.typepad.com/penny_carnival/2008/06/the-end-of-the.html

We use to bake challah bread like this for easter at the bakery i worked at in highschool (each strand a different, saturated color). It was a little scary, but kids really loved it.

pennycarnival - that's really classy and cute!

my question is wouldn't you be able to taste the dye if you're using that much? not sure if I would like eating it...

Thanks, goodLife! It was a hit at the party.
I don't remember it taking a ton of coloring and I don't remember being able to taste the coloring in it, but it's quite possible that my palate isn't as sharp as it should be.
Use a recipe or box mix for YELLOW cake, not white. I tried both and the yellow seemed to make the color bolder.

That is so freaking awesome!

I've never seen a cake this bright! love it

I make a similar cake but it's a checkerboard. You use 3 colours. Pipe a large ring along the outer edge of the cake pan, a middle ring and a big dollop in the middle. (A helper is great as you need to be quick). Do the second layer of the cake but alternate the colours. When you cut it, viola! it's a checkerboard.

And no, you can't taste the food colouring.

so cool!

It's just so insanely cool...I actually bought all of the ingredients to make this tonight - I plan to make it for a family dinner party tomorrow!

It's my daughter's birthday tomorrow so we thought we'd try it.

While this looks quite giddy, I could never eat it...Some people can taste food coloring, and I am one of them. I found this out years ago when a friend made mint jelly and thinking that it looked too blah, added some green food coloring. I'd never had mint jelly before, but was eager to try it. (never again! it tasted terribly bitter and "chemically" to me, but not to the other people at the dinner)

:) Great idea!

This reminds me of that scene on 'Hook' where they have that food fight.

i don't know. kind of gross to serve a cake made with diet sprite??? to children. not to mention the food coloring, crappy box cake, etc.

I made this cake for my boyfriend's birthday last week, and we both loved it.

It is heavier then expected though. We figured it would be light, but it's got more of a sponge cake feel to it. It also made an enormous amount of cake. I doubled like the recipe said, and really should have used three cake pans (I had a bit of leakage!). Next time I won't double. The frosting is fabulous though. It would be perfect for the cupcakes in ice cream cones too!

omg, these as cupcakes in ice cream cones is a FANTASTIC idea!

anyone make it using good ol oil/eggs instead of the soda? Is soda needed to make it hold the dye better or give it a certain texture?

I made a three layer cake using the joy of cooking's white layer cake recipe-- it turned out great! Honestly, with the gel food coloring, the amount of dye is negligible. It takes so little to get good results.

Best. Cake. Ever.

I baked it secretly and frosted with plain white icing (clouds), then surprised the kids with it. They were thrilled enough that they were getting a surprise cake, but when I cut it open to reveal rainbows inside, they flipped.

A huge hit! Thanks.

Can't wait to try this!

Forget kids my gay friends would get a kick out of these.

That's super cute!

Here's my (easy!) version of a rainbow cake.
http://pamperingbeki.blogspot.com/2008/12/duck.html

How cute would it be to make it rainbow inside AND out?!

Budino, I made one recently using cake mix and eggs, water, etc. Diet Sprite id NOT necessary and in my opinion, pretty gross. I used a yellow cake mix and with two boxes of mix and two pans, I had a lot of overflow. If I were to do it again, I'd use three pans or only one box of mix.

To make it a bit healthier, I substitute apple sauce for oil. No chemicals (like there are in diet soda), less fat (though there is still fat in the eggs), and no perceptible difference in taste or texture.

I've heard it's also possible to substitute a can of pumpkin for the eggs/water/oil but I imagine that would change the color and flavor of the cake and in an application like this seems like a bad idea.

Emily S, I sometimes put pumpkin into my white cakes. Tastes great. Very moist.

hi this is amazing! im thinking about doing it for my friend,
how do i get it to be rainbow inside!?

I made this in the cake form and cupcake form on two separate occasions and it was SO GOOD both times! It was super easy (albeit messy...), and you couldn't taste the food coloring. This next party I'll probably make it with regular sprite cause there will be lots of children. And you know, we don't want to completely overload them with fake. Not that sprite is a real food, but anyway...

I've made this a few times now. Both cakes and cup cakes. I like taking a box of white cake mix and using the normal recipe with food coloring. The low fat recipe tastes fine but it's all about the colors not the reduced fat. Also try the neon food coloring! I made a cake with 9 different color layers!

i love rainbow cakes! i made rainbow cupcakes for my sons school and also made a rainbow layer cake for thanksgiving.

http://teamwiking.com/2009/04/10/how-to-rainbow-cupcakes/

Fun! I found this a year late via the rainbow pancakes post. Here's another rainbow cake -- more work, more frosting, and less fat free, but also very pretty, in a different way.

As a lover of all things rainbow...especially baked goods! I have done the rainbow cake...rainbow pancakes and rainbow cupcakes. I thought I would share my own version of a different take on rainbow cupcakes.
http://paperlili.blogspot.com/2010/07/and-just-like-thata-decade-flashed.html