Love and Olive Oil

Rainbow Cake

I think you all know what this time of year is. Yes, I know it’s Thanksgiving, but more importantly, it’s also Robin’s birthday. My little sister. Who loves cake. And every year she chooses to visit us for her birthday. She could spend her precious Thanksgiving break anywhere, and yet for the past 3 years, without hesitation, she’s come to Nashville. Honestly, I think it’s because of the cake.

Last year’s cake was pretty darn delicious (and pretty tall too) in all its chocolatey goodness. But I really think I’ve outdone myself this year.

What, you say? That cake doesn’t look like anything special… it looks like just a plain old white cake with a shaky piped greeting…

Well, I say to you, let me cut you a piece…

Bam! Didn’t see that one coming, did you?

Indeed, I tackled in the infamous Rainbow Cake, as seen on Martha Stewart and I’m sure countless other blogs. So no, it’s not original. But that doesn’t make it any less fabulous.

I’ll admit, it wasn’t easy, and I joked that this cake was doomed from the start. From an overly-bubbly and oddly textured cake, to cake layers flying through the air and landing on the floor (thanks, cats!), which lead to a necessary rebaking of the green and yellow, to fingertips meeting with sharp knives, to an entirely too-large batch of buttercream that kept my mixer huffing and puffing for nearly 75 minutes… no, it wasn’t easy at all. But the reaction, the surprise when you make that first cut, that alone made it entirely worthwhile. Robin has officially declared this her Favorite. Birthday. Cake. Ever. Success!

I better start planning now, because I really have no idea how I’m going to top this one next year…

Rainbow Cake with White Chocolate Buttercream

This recipe is a bit uneven. I used 6″ pans, and the layers were too thick and and I had way too much frosting. I think it’d be better suited to a 7″ or even 8″ cake, so adjust as necessary depending on the size of your cake pans.

Cake recipe from Cooks Illustrated. Frosting recipe from Martha Stewart.


For Cake:
2 1/4 cups cake flour (9 ounces)
1 cup whole milk, at room temperature
6 large egg whites (3/4 cup), at room temperature
2 teaspoons almond extract
1 teaspoon vanilla extract
1 3/4 cups granulated sugar (12 1/4 ounces)
4 teaspoons baking powder
1 teaspoon table salt
12 tablespoons unsalted butter (1 1/2 sticks), softened but still cool
Red, orange, yellow, green, blue, and purple gel food coloring

For Frosting/Filling:
2 1/2 cups granulated sugar
10 large egg whites
2 pounds (8 sticks) unsalted butter, cut into tablespoons, softened
2 teaspoons pure vanilla extract
1 pound best-quality white chocolate, melted and cooled


Preheat oven to 350 degrees. Prepare your cake pans by first liberally buttering the pans, then line the bottoms with parchment paper rounds. Butter the rounds and set aside.

Pour milk, egg whites, and extracts into 2-cup glass measure, and mix with fork until blended. Mix cake flour, sugar, baking powder, and salt in bowl of electric mixer at slow speed. Add butter; continue beating at slow speed until mixture resembles moist crumbs, with no powdery streaks remaining. Add all but 1/2 cup of milk mixture to crumbs and beat at medium speed (or high speed if using handheld mixer) for 1 1/2 minutes. Add remaining 1/2 cup of milk mixture and beat 30 seconds more. Stop mixer and scrape sides of bowl. Return mixer to medium (or high) speed and beat 20 seconds longer.

Divide batter evenly between six medium bowls. Add enough of each color of food coloring to each bowl, whisking, until desired shade is reached. Transfer each color to an individual cake pan. Transfer to oven and bake until a cake tester inserted into the center of each cake comes out clean, about 15-25 minutes (working in batches if necessary).

Let cakes rest in pans for 3 minutes. Loosen from sides of pans with a knife, if necessary, and invert onto wire rack. Allow to cool completely. At this point, the layers can also be wrapped in plastic wrap and frozen.

To make frosting, put sugar and egg whites in the heatproof bowl of an electric mixer, and set over a pan of simmering water. Whisk constantly until sugar is dissolved and mixture registers 140 degrees on an instant-read thermometer.

Transfer bowl to an electric mixer fitted with the whisk attachment; beat on medium-high speed until fluffy and cooled, about 10 minutes. Continue beating until stiff peaks form.

Reduce speed to medium-low; add butter by the tablespoon, beating well after each addition. Beat in vanilla and white chocolate. (Any leftover frosting can be refrigerated in an airtight container up to 3 days or frozen up to 1 month.)

To assemble, using a serrated knife, trim tops of cakes to make level. Place four strips of parchment or waxed paper around perimeter of a cake stand or lazy Susan. Place the purple layer on the cake plate. Scoop a 1/2 cup (or more for a larger cake) buttercream filling over the first layer and spread with a small offset spatula so it extends just beyond edges. Repeat process with blue, green, yellow, and orange layers.

Place the remaining red layer on top, bottom-side up. Gently sweep away any loose crumbs with a pastry brush. Using an offset spatula, cover the top and sides with a thin layer of frosting (also use any of the excess frosting visible between the layers). Refrigerate until set, about 30 minutes.

Using a large offset spatula, cover cake again with remaining frosting.

All images and text © / Love & Olive Oil

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  1. it’s amazing! thanks for share

  2. I tried it with 8″ pans today and the layers were too thin. I know you said the 6′ was too small, but I’d rather a fluffy cake than flat so I will try again!! Its for my daughter’s birthday! Luckily I attempted it a few days early just in case I messed up. :)

  3. wow, this is amazing. i’m attempting this cake right now, as we speak. but i dont think mine is going to be nearly this gorgeous!

  4. I’m gonna make this cake someday.
    [adding to bucket list]

  5. OMG……The second i saw this cake i was blown away….I haven’t seen this cake before so its no surprise that i was shocked…..but you have done such a great job on it…..ill defiantly try to make this sometime. The pictures are defiantly impressive.

  6. Is this vanilla-flavored? And you said there’d be too much icing, so should I divid the icing recipie in half?

  7. That is absolutely and utterly beyond stunning. Wow. There are no words.

  8. One word- WOW. I really want to make this, but am afraid to! I would be in the kitchen ALL day.

  9. Amazing :D I’ll sure try it.

  10. I can’t believe you made this! amazing!

  11. WOW this is pretty special, I think I’ll give it a go when I’m feeling up to it, for now I’ll just stare at yours and be jealous!

  12. Totally Amazing. – How long did it take from start to finish?

  13. This is such a beautiful cake!How far ahead to you make this in advance? How do you serve it? I will need to serve 10-15 people.
    Thanks in advance for any advice!

  14. Oh my god! -that is one of the most beautiful cakes I’ve ever seen. Was it hard to make? I think I’ve found my dream cake for my birthday :)
    And where did you find the recipe?


  15. This is a wonderful recipe, thanks so much for sharing. You did a great job with the images too; I will definitely try this recipe this weekend.

  16. I feel inspired! It’s been a while since I had time to make a cake, but that used to be one of my main hobbies. Thank you for inspiring me and I WILL make time to make this cake :)

  17. It’s amazing!!! Congrats!

  18. i know this is late for a comment, but i thought i would add, i am baker did a version of a rainbow cake, using only fruit juices to attain the colors. seemed like an interesting idea, and it would add more flavors to the layers, i think it might be fun to try.

  19. AWESOME! I have never seen anything like this!

  20. This cake is jaw dropping. I have never seen a rainbow cake as perfect and colorful. I MUST attempt it. I think I will try doing it gluten free as my fiance is celiac, but since GF cake doesn’t rise as much, it woudl be suitable for the number of layers required. Anyway – AMAZING job. I HAD to comment.

  21. I love these rainbow cakes, and even if it isn’t the “original” I think it is still amazing!

  22. This cake is so cute and so nicely made! Is it possible to make a rainbow cake without baking each color separately?

  23. That is AMAZING! I can only imagine how much time that took! Seriously…jaw on the floor amazing!

  24. This rainbow cake is so coool. I want to make this!

  25. I meant to mention this when I saw you last night at Porta Via but I saw some baking-fanatic cousins of mine in Ohio this weekend and happened to mention your blog. They both are avid readers and mentioned the rainbow cake! I wanted to pass their kind words along. They couldn’t get over how amazing it was. And I totally agree — this is SOME CAKE!

  26. HI,

    I used your recipe to make this cake and its the best cake I have ever made. Thank you. I will be making one for my brothers wedding next month and I am looking forward to their faces when they cut it!

  27. hahaha, nice surprise, I love it!


  28. WOW! This cake looks amazing! I just got done making this cake. I used 8″ round cake pans and doubled the recipe. That cake tastes AMAZING! and looks great too! You did a fantastic job, I can’t wait to see what mine turns out to look like. I made it for my own birthday! (:

  29. So much frosting! So little cake lol

  30. This is even prettier than Martha’s. Now that is a difficult feat!

  31. This is truely awesome! Do you think the same effect could be obtained by just using a betty crocker white cake mix (where you only add eggs,water, and oil) and just adding the food coloring?

  32. Wow that cake captured my attention on the front page, no wonder this is the most popular post. This looks like it will be the perfect cake for my nieces birthday that is coming up, so i’ll test it out and see if it turns out as nice as yours :)

  33. This cake is beautiful. The colors are so vivid.

  34. I was just wondering – did you use confectioner’s sugar in the frosting? Or granulated? I assumed it was confectioner’s… but mine seemed… off. Perhaps I did something else wrong.

    • This particular frosting is a swiss meringue, which calls for granulated sugar. Sorry for the ambiguity, I’ve updated the recipe to be more specific. :)

  35. What a vibrant investment of time! I may not be up to the challenge of all those layers, but I love the idea that I now can color-coordinate the inside of a cake and surprise everyone. Thanks!

  36. This is AMAZING!!! Must be so yummy!

  37. Now this I didn’t expect. So much yummyness in the first slice. And im sure it tastes as great as it looks.

  38. I LOVE THIS CAKE! I am currently wracking my brain for occasions where I might be able to make it for a crowd… I love it that much! I will make up some kind of special occasion if one doesn’t present itself soon… gay pride, maybe??

  39. i love this cake it really very nice sososososos lovely . incredible thinking . WOW

  40. Wondering if it would work with a white chocolate ganache instead of the buttercream?

  41. This cake looks incredible!!

  42. That is a beautiful cake! I love rainbows and this makes one believe they can now be eaten :)

  43. This is so cool! A friend of mine made a similarly colored cake that was swirled, but yours is much more elegant. So playful!

  44. ok so i am going to try this! so excited. I just wanted to know, I want to make sure the colors are as bright and vivid as you have here. I’ve never used gel coloring before (or any coloring really) and I have no idea how much to add into the batter. Do the cakes come out of the oven looking as bright as the batter with the coloring in it looks? Or does it get duller in the oven so then I would need to make it extra dark in the batter?
    it’s gorgeous!

  45. So i attempted this recipe a couple months ago pretty much an epic fail. What did you do for the layers of cake be even? Also did you modify the frosting recipe for it to be as much as it should be?

    • Sorry to hear! I divided the batter using a kitchen scale so each layer had exactly the same amount. And then when the layers had baked and cooled I leveled them, making sure each layer was the same height. The cakes rarely come out of the oven perfectly level so this step is typically necessary. The frosting recipe posted is exactly what I made. My cakes were 6″ and I had about twice as much frosting as needed. Probably even too much for 7 or 8″ cakes, but frosting can always be frozen and used for another purpose.

  46. LOVE love love this.


  47. F-A-B-U-L-O-U-S!!!!!!!!!!!!!

  48. I’ve seen several of these, but yours is by far the most beautiful. I like the thicker cake layers. Sent this link to my granddaughter, who made the cake for a New Year’s sleep-over, and she is just 12! Thanks for the recipe.

  49. This is a link to the post on Whisk-Kid’s blog, as Serena mentioned, she was the one who made the cake on Martha Stuart:
    Your cake is aboslutely gorgeous, I just wanted to give Whisk-Kid a nod!

  50. As a Color Specialist, I’m impressed too! I’ll have to write about this beauty

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