Easy Rainbow Cake

This week we celebrated the last birthday of this year’s birthday season. We have a lot of spring birthdays in our family (extended as well as immediate). It’s a lot of fun, but as the school year is winding down at the same time, it makes for a busy season.

One birthday child wanted Grandmom’s chocolate cake for his birthday this year. Another wanted a store-bought chocolate chip cookie cake. The third, our birthday girl, requested a homemade rainbow cake, and how could I say no to that? I think my katieishness has rubbed off at least a little bit. Birthday Girl first had a rainbow cake for her third birthday, so of course I had to go back to look at pictures from back then and wonder over and over again how it’s possible that she’s 15 now. (Seriously, how?!)

I am by no means an expert baker, but this is so easy that I had to share. I used a boxed cake mix this time, but you could easily use any white or yellow cake recipe instead. The mix I had was for a white cake, but I used the full eggs instead of just the whites, so the batter was yellowish starting out. It really doesn’t matter, because once you add the food coloring—particularly if you use the gel kind—you’ll get beautiful rainbow colors.

Once I mixed the cake mix, I divided it into six different bowls, as equally as I could. Together with my baking assistant, I colored each bowl a different color—red, orange, yellow, green, blue, and purple. A little goes a long way with the gel food coloring, so you really don’t need much. As I told my baking assistant, though, you have to mix well to make sure all of the batter has been dyed.

I used two round cake pans this time, so after I greased them, I started with the red batter and poured it right in the center of each pan. Then I took the orange and poured it right in the middle of the red. I did the same with all of the colors, finishing with the purple. Look at those rainbows!

My baking assistant thought I ought to make it a little fancier, so I took a toothpick and dragged it through the batter a few times. I’m pretty sure the only thing that did was make the cakes look a little extra pretty while they were still in the pans, but it made my baking assistant happy, so it was worth it.

Even the aftermath is pretty.

I baked the cakes according to the directions, and then admired them before taking them out of the pans. I actually left them in there for way too long and had some trouble removing them (we lost a few chunks out of the bottom), but once I assembled the cake you couldn’t tell.

My very favorite store-bought cake frosting is Rainbow Chip, but I wasn’t able to get that this time. Instead we ended up with a Oreo vanilla frosting that turned out to be really good. Rich for sure. Birthday Girl loves Oreo anything and said the frosting made the cake look like a cloud, so it was a complete win. She also loved that its plain appearance hid the rainbow inside. (It IS fun to surprise someone this way!) She did NOT want sprinkles, by the way, and she’s lucky I found that out before I coated the whole thing in them.

Somehow I neglected to get pictures of the finished cake before it was half gone, but here you go. If that isn’t joy on a plate, I don’t know what is.

I’ve made rainbow cakes a few times now, and they are crowd pleasers every single time. I’ve even baked a rainbow cake in a rectangular pan in order to serve more people. To do that I started with red on one half of the pan and purple on the other. I layered the colors as if I were using two separate pans. One side looked like the rainbow above, and the other was reversed. As the circles spread, they ran into each other and ended up looking very cool. So that’s another way you could go. However you choose to do it, it will impress people.

Whatever the occasion you have for a rainbow cake, I hope it will brighten your day as much as it has ours!