even more rainbows (the cake and cupcakes)

Geez, will this rainbow party every end? Last post, I promise. Just want to share with you the rainbow cake and cupcakes, neither of which are my idea. The original rainbow cake is found HERE at Whisk Kid (I remember when I first spotted this cake two years ago.) And I borrowed this method of making rainbow cupcakes from Family Fun.


cake and cupcakes

For dessert, I made the now-classic rainbow layer cake, but I, ahem, used store-bought boxes of white cake mix. Homemade buttercream, though. Above is all that was left after the party.

I made only five layers. I divided the first box of batter into four 9-inch cakes. I divided the second box of batter, too, using one quarter for the last color of cake, and using the rest to make rainbow cupcakes. To color the batter, I used Americolor Soft Gel Pastes, Red Red, Egg Yellow, Electric Green, Sky Blue and Regal Purple. I needed two batches of buttercream frosting.


Because I’m a make-ahead kind of person (translation: I’m super crazy nutso stressed when I throw parties, so anything that I can do ahead, I do ahead), I used the Smitten Kitchen’s tips on freezing baked layers of cake. I made all the layers and the cupcakes, wrapped them all well with plastic wrap, and froze. The day before the party, I prepared my frosting, then took out the layers and frosted and stacked the cake almost immediately (ie. while still a little frozen, though the layers thaw quickly). I put on a crumb coat, returned the cake to the fridge for an hour or so, took it out, frosted it again, then kept it in the fridge until the party the next day.

For the cupcakes, I removed them from the freezer, unwrapped them and let them thaw completely at room temperature before frosting with a disposable decorating bag and star tip. I also keep my cupcakes in the fridge the night before a party.

Look, even the wrapper is cool.


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  1. Victoria (The District Chocoholic) says

    I have been lusting over a rainbow cake for ages and desperately want to make one…but those cupcakes! Even more beautiful, I think.

  2. The Vanilla Bean Baker says

    Your daughter must have been so delighted with her entire party but having her very own rainbow cake and cupcakes must have been such fun for her.

  3. sugarswings says

    haha, was just wondering if you posted this yet! a rainbow layer cake is on my to do list too…great job on cake and cuppies and i'm sure they were a huge hit!! i <3 anything rainbow!

  4. Jenn @ BentoForKidlet says

    So yummy and colorful! I've been trying to limit my sugar lately but I can feel my willpower fading 😛

  5. naomi says

    These look gorgeous! I'm with you, on doing as much as possible the night before too b/c I'm also a stress case when it comes party!

  6. Katrina {In Katrina's Kitchen} says

    You never need to apologize for rainbows in my presence. These are specracular. I need to check out this froen-cake tip though…I may get a little crazy too when party planning. :)

  7. Christine says

    so pretty! i am soo dying to make a rainbow cake but i don't know if i have it in me to do all the layers, heheh.. yours looks great!

  8. Dharma says

    I reached your blog through Sugarbell and I think magnifico.Aunque rainbow cake is not yours has been great and you have made me smile by saying he had bought the mixture made. Congratulations on that organization's birthday. Greetings from Madrid.

  9. Sarah says

    Love it!!! Would you say that boxed cake mix works just as well as from scratch? I’m researching rainbow cakes and wondering if I can save myself the hassle of making it from scratch. I’m worried it it will be too fluffy but yours looks beautiful!

    • meaghanmountford says

      Though I love a homemade cake, and I rarely use mixes for baked things (especially sugar cookie mix, never!), the one exception I make is for cake. It’s such a timesaver, and I often like the boxed cake even better than homemade! The boxed cake mix works especially well for rainbow cakes if you opt for the white cake mix. The color shows up so well. So yep, I’d say yay for the cake mix. But with homemade buttercream :).

  10. Sarah says

    Thanks so much! I’m attempting to tackle this baby today :) Definitely going with boxed, to save a few headaches and not to mention dishes!

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