Rainbow Birthday Watermarble Nails and Cake with TUTORIAL

When I got out of class on Thursday I didn’t have too much of a plan for what I wanted to do the next night for my 22nd Birthday. All I knew was that I had my heart set on making a rainbow cake. Little did I know that the cake and the entire night would turn out to be just perfect! My mom is visiting from Hawaii and whenever we get together we always end up whipping up some amazing tasty treats. Mom kept asking me what I wanted to do on Friday and I finally decided that I wanted to have a few friends over for some food and good times.

This post has lots of photos as I wanted to share with you all the way I made the rainbow cake pictured below. Isn’t it just beautiful?! It went along perfectly with my funky rainbow water marbled nails, using Bettina Cosmetics shades in Red, Starfish, Yellow, Green Apple, Aqua and Purple.


Here are the nails all up close and personal along with my falling star midi-ring form So Nailicious Boutique which I wear all the time now. As always I was having trouble deciding which design I wanted to go with and simply ended up doing them both together, one for which I have a tutorial for HERE (the outer nails). I’m still in the process of figuring out video tutorials so bare with me loves!


Alright so lets get to the cake making. I’ve heard they have rainbow cake mixes in target now which just shows how popular they have gotten. I myself am surprised this is my first time doing this as my love for rainbows is oh so vast. First off I want to provide you with some useful links that I utilized throughout my process:

White Cake recipe from Add a Pinch– you can use a box instead but it won’t come out as tasty as if did using the recipe

Cream Cheese frosting recipe– you could also use a pre made icing to save time

My inspiration from Bird On a Cake and the tutorial I followed from Omnomicon.

If you ever feel that my recipe/tutorial is missing something I would reference the links above. I’ll put a summarized recipe at the end of this post to make it easy for you to follow if you decide to try this out for yourself!

You are going to want to start by taking out your cream cheese and butter for the icing and cake to get it to room temperature. Next start hitting up that oven to 350F. Make your cake mix and then equally separate it out into six bowls with six separate spoons. You can eye this part or using a measuring cup and spatula. Drop in your selected gel food coloring for each layer and begin mixing.


Using gel food coloring will help the colors stand out. I found some great colors at my local grocery store and I used all but the pink and blue in the pastel pack.


Keep mixing in your dyes till it is fully incorporated. If needed add some more coloring to the batter, take the yellow for example.


Next with two lined (buttered and floured) 9×9 cake pans you can begin making the concentric circles of the layered rainbow cake. Begin by taking the red (magenta in my case) and pouring around 3/4 of it or more into the bottom of the pan. Do your next color but pour less of it making sure you have a nice circle that is pushing out the previous color. Keep doing this with each color pouring less and less till you get to the purple, leaving much of it for the bottom of the other pan. Do this same process in the other pan but in an opposite pattern as you will have more of the purple, blue etc. etc. Here is a photo of both pans poured and ready for the oven. I have a cupcake tutorial at the end of this post that shows these steps one by one. 


Stick the cakes in the oven for 30 minutes or until they pass the toothpick test. I made the cream cheese frosting while they cooked. When they are done let them cool then flip them out onto a plate. I flipped one around and left the other face down so that they could be placed evenly on top of one another. A little bit of the left one came off in the pan so you can already start seeing the inside of it, so awesome!


Spread some icing onto your bottom cake and then put them both together, as you can see pictured below.


I separated and colored my icing the same way as the cake batter and then put them into zip-loc bags so I could pipe them out through a cut corner of the bag. My photo below is after I used them to ice the cake. I kept squeezing out some onto my fingers as it was just so decadent.


You can ice your cake anyway you like, I did it the way below. Placed one of the lei’s my mom brought with her for me around the cake as we were so proud of its outcome.


Alright now for a few photos that are bound to make your mouth water!



As I mentioned before I did a quick rainbow cupcake pictorial for you to see the water each layer is poured. These came out great as well!


What you’ll need:

  • Ingredients for white cake found HERE or two white cake mixes and ingredients
  • At least six gel food colors (if you only have four primary colors you can mix them to make two more)
  • Two 9×9 round pans or cupcake tins large (12)/small (24)
  • Cream Cheese icing and Zip-loc bags
  • Six bowls and spoons


  1. Preheat oven to 350F. Make cake batter and equally separate it into six bowls with separate spoons.
  2. Color the separate batters with gel food coloring fully incorporating each color adding more if needed for vibrancy.
  3. Flour your pans and begin pouring your colors one after another. Pour out around 3/4 of the first color on the bottom of one pan leaving some for the top of the other. Keep pouring one color after another doing less and less each time till you get to the last color.
  4. Repeat this process in the opposite fashion of colors for the other pan.
  5. Bake in oven for 30 minutes or until cakes pass the toothpick test. Make icing during this time.
  6. When cakes are done let them cool before taking them out of the pan.
  7. Flip them out leaving one face down. Ice this cake and place the other on top.
  8. Pipe out icing as desired and enjoy one crazy awesome cake!


I wanted to thank you all so much for all the thoughtful birthday wishes I received this year, it was truly humbling and I couldn’t of asked for a better birthday this year!

Please let me know if you have any questions or concerns about my post! I am so excited I get to share this totally awesome occurrence in my life with you all!

Thank you so much for reading!

Corynn <3

2 observations on “Rainbow Birthday Watermarble Nails and Cake with TUTORIAL
  1. Amandah

    WOW, looks like you had a fun time with your mum.
    The cake looks great as do your nails. One of my cousins made a rainbow cake for one of my nephews a few years ago, it turned out really nice, thought a little on the pudding side as I think she used too much colouring too the mixture.

  2. Pingback: Tillie Polish Sweet Collection Nail Art & Review | Mucking about and making a Fuss in the wonderful world of Nail Polish!

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