Six Layer Rainbow Cake

I hope you love looking at this rainbow cake as much as I do! It makes me giddy every time I remember the day my friend and I decorated this baby. It was so much fun and the end result still takes my breath away. I originally shared this cake over at Kojo Designs as part of the Color Your Summer series, but it’s too fun not to share the whole post over here, too.

A little while back, a close friend of mine called me up to ask if I wanted to help her decorate a cake for a preschool fundraising event. It just so happened that our schedules aligned perfectly and I was able to spend the day playing with icing and a fellow cake-decorating lover! Since the name of the preschool is “Rainbow School,” a rainbow theme cake was the obvious choice and since my friend, Emily, loves to do cakes over the top, she signed me up for a six-layer, I-don’t-even-know-how-many-colors rainbow decorated masterpiece. After talking through the logistics, and knowing that the preschool wanted a show cake in addition to the sheet cakes they would be serving to guests, we decided that decorating a styrofoam cake would be easiest. We wouldn’t have to figure out how to support and transport such a large cake, we could make it ahead of time, and we wouldn’t have to worry about the flavor of the icing after dumping ten gallons of food coloring into it. Styrofoam cake forms can be purchased inexpensively from cake supply stores and you can even purchase them through Amazon (affiliate link) here – Styrofoam Cake Forms.
We used royal icing to decorate the cake – it colors well, holds its shape, and dries hard. We had sketched out the layers ahead of time and planned a color progression so that we would be able to fit all eight gazillion shades of color on the six layers. 

We started with the top layer and iced it in white and light pinks, gradually moving into darker pinks and reds as we stacked subsequent layers. After the reds, we got into a groove, deciding that we liked a more blended look. Rather than layering each new color shade below the previous, we started blending the shades together, fading out the lighter shades and fading in the subsequent darker/changing colors.

Emily is a color-mixing pro. We’d whip up a triple or quadruple batch of icing (we had two Kitchen-Aid mixers going at the same time) and then plop icing into five or six different bowls and start adding color. About mid-day, Emily took over all the color-mixing and I did all the piping. She is so good at getting the perfect shade!!

We started at about 10 am and finished at about 6 pm, with both of us working pretty much non-stop the whole day. It was SO much fun! I loved having the opportunity to watch Emily work her magic and see this rainbow of icing come together. And it was really cool to see how our very opposite creative personalities worked together. I was like “We have to make sure all the dots are uniform and perfectly placed” and she was like “I wonder what would happen if we just added a little purple to this orange-ish color.” And it turned out more spectacular than I could have imagined!

So that’s the rainbow cake! I’m adding a few affiliate links below for some great resources through Amazon in case you’re itching to do a little fake cake decorating!