Easy Rainbow Cake! (with cake mix & frosting!)

You don't need any fancy baking skills or experience to make an easy rainbow cake using cake mix- the quick and simple version of  the infamous rainbow cake that Kaitlin from Whisk Kid created and blogged about, then shared on the Martha Stewart show!

(This photo is of my version)

easy rainbow layer cake

Her cake is beautiful & as soon as I saw it, I wanted to try it. I tried it for a family gathering for my 3 year old's birthday and I wanted to do it the quicker and easier way. So, today my friends, I'm going to share with you the easiest way to recreate the rainbow cake with cake mix and store-bought frosting.

How to Make a Rainbow Layer Cake

Here's what you'll need:
easy diy rainbow cake
(I only used 3 of those frosting containers for mine)

Easy Rainbow Cake Recipe

1. Start by making the cake mixes as directed on the box (use WHITE cake mix- not yellow, and only egg whites or the colours of the cake won't turn out as well).

2. Divide the batter into 6 bowls & add food colouring in your desired colours.

3. Bake in round, lined cake pans (watch carefully since they are smaller than the mix expects, and will be finished sooner).

4. Take each cake out of its pan & let cool. Then wrap and put in the freezer. (I did mine overnight just because that's what time I made mine, but you only need to leave it long enough that the layers are easier to work with than soft cake)

5. Plop the first layer of cake on your place (icing underneath will "glue" it in place) and frost the top of it, then add your next layer of cake, frost the top, add the next layer, etc. until your colorful layer cake is all assembled like so:

easy 6 layer rainbow cake

6. Finish frosting the outside of the cake (be generous with your frosting between layers & on the outside, to prevent crumbs showing through on the outside, and to make it look cooler when you cut it ;)

You can leave it plain or add decoration to it. Here's what I did with mine:

And here's what the slices look like:
easy rainbow cake
Easy Rainbow Cake

Isn't it pretty? :) I was so happy with the way it turned out! Someday I'd love to make Kaitlin's deluxe version, but for this occasion, the store-bought mixes & frostings did the trick!

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easy to make rainbow cake

If you're looking for other rainbow ideas, there are a bunch in my St. Patrick's Day Ideas Roundup!


  1. I made Whisk Kid's rainbow cake for Jessie's 5th birthday! It was really fun to make and turned out stunning, but I will admit my family didn't love the Swiss Meringue Buttercream, especially the kids.

    So fun! I love all the rainbow colors!

  2. Oh, and a Happy Birthday to you! (yesterday) Hope you had a great birthday!!!!

  3. How pretty!! I am visiting via ABC & 123 - so glad I've found this!!

  4. How much of the food coloring did you use? I tried this, once, and my colors were so dull...=( Yours is so pretty!

  5. Hi Jayma, I used gel food colouring which definitely helps make the colour richer. I just kept adding it until the batter looked about the colour I wanted & that worked great! (Also, using a WHITE cake mix with only egg whites makes a big difference for the colour showing through)

  6. I LOVE easy beautiful cake ideas!!! I will try this!!

    Would you mind linking this up on my blog PLEASE??

  7. I Love this! We just posted our 2nd Kitchen Fun and Crafty Friday Link Party today and would love for you to share this! http://kitchenfunwithmy3sons.blogspot.com/2012/02/kitchen-fun-and-crafty-friday-link_16.html

  8. That looks great! Thanks for sharing it with Six Sister's Stuff Link Party. We hope to see you back next Saturday!
    -The Sisters

  9. I just made a cake like this and used lemon cake mix. I was a little worried how the yellow colored cake mix would affect the colors, but it turned out great. I did use food color from a professional cooking supply store, but just letting you know it can work.

  10. I am going to make this tomorrow for my daughter's bday this weekend! How long does it take for the cakes to defrost if they are left in freezer over night? Do you know? Thanks for the recipe!

    1. It has been over a year now since I made the cake & I haven't done it since! I can't say I remember for sure! I would suggest assembling the cake a couple of hours before you want to eat it (or earlier), but I'm not totally sure!

  11. This is the prettiest cake Ive ever seen! My son would flip if I made this for him. Thank you for sharing the recipe.

  12. This is so pretty and the kids would really love this one for a birthday party.
    heather hgtempaddy@hotmail.com

  13. I think I'll do this cake for my daughter!

  14. Debbie White BeattieApril 10, 2017 at 6:00 AM

    This cake is beautiful and I can't believe how much work you've done to make it

  15. This is a beautiful cake,bet it was delicious !

  16. I adore this rainbow cake to excite the child about her celebration. Truly, memories in the making.

  17. That is fully awesome. I love all the colors, and of course, the frosting doesn't hurt, either. That's a fun cake!

  18. I've been wanting to make a rainbow cake. They look really good. I know my daughters would love one too. My oldest is going to have a birthday next month and I'm sure she'd love having a rainbow cake.

  19. This is such a beautiful cake! Layered cakes are always so intimidating to me. You did such a good job!!

  20. Wow.. Happy birthday to her!! And this turned out so cute even it's made as easy as that.

  21. This looks delicious and amazing! I was intimidated to try something like this, but you make it look so easy!

  22. I've used Betty Crocker products before and it's amazing. That raindbow cake is looking quite delicious!


Thanks for taking the time to leave a comment- I love reading them! :)
~Heather Lynne