Rainbow Cake

For my son's birthday this year, I was looking for a fun cake... but not a theme cake. I had spotted some awesome ombre cakes on pinterest and was really hoping to try that in orange for him... but when I showed him some of the pictures, he emphatically told me he wanted the rainbow cake. So the rainbow cake it was.

And what a fun cake it was! After checking out a bunch of different pinterest links, I felt like I was ready to tackle it. Since it was for a five year old who doesn't even really like cake, I decided to keep it simple and use a dressed up cake mix. The colors were going to make it exciting... he wasn't even going to care about the taste. However, I decided to use a pudding filling in between the layers and then I frosted the whole thing with our favorite whipped cream cheese frosting and the cake was seriously delicious. Best birthday cake ever and the first time in nine years that a birthday cake has been finished. Usually, we pull it out for pictures and then the next day I throw it all away since no one in my house likes cake. But not this one. Nope, this one was delicious and actually eaten!

This cake was a lot of fun to put together and really not that hard. The hardest part was getting the layers even and keeping such a tall cake from turning into the leaning tower of cake! I baked the cakes the night before and then stacked, filled, and frosted them the next day.  But you could do it all in one day pretty easily.

The next time you want something flashy and fun, but still simple, I think this cake is a great choice. If you want some more inspiration, look here ( I love her ruffle frosting on top), here (love the Skittles rainbow on top... but that was a bit too frilly for my five year old), here, and here.  And here's how I made mine:

Cake:
2 boxes white cake mix (white cake mix colors the easiest)
oil as called for on the box
eggs + 2 as called for on the boxes (so, if your box calls for 3 eggs, you'll use 4 eggs per boxed mix...)
buttermilk in place of the water called for on the box
food coloring (neon or gel colors work best here to get the most vibrant color)
as many round cake pans as you have, well greased
small mixing bowls
kitchen scale (I highly recommend this!)

Filling: 
recipe source: Not Just Cute
1 box Instant vanilla pudding mix (big or small... doesn't matter... I used a big one since I had a lot of cake layers to sandwich together)
1 container Cool Whip, thawed( big or small, depending on whether your pudding mix was big or small... I almost used all of a big container)
1/2 the milk called for on your chosen box of vanilla pudding


Whipped Cream Cheese Frosting:
recipe source: Allrecipes
1 8 oz. pkg. cream cheese, softened
1 cup powdered sugar
1 1/2 cups whipping cream, chilled
1 tsp. vanilla
1/8 tsp. salt

Cake:
1.  Preheat your oven.  Grease your round cake pans really well and/or line with parchment paper. 

2.  Mix both boxes together, according to the package instructions.  A big bowl and a stand mixer come in really handy here.

3.  Once you've mixed everything well, prepare to divide your batter.  I only had two pans and I knew I didn't want to have to clean them and bake another round more than twice so I settled on six colors.  If you have more pans, feel free to use as many colors as make you happy.  Six made me happy enough.  Divide the batter evenly between your six small bowls.  This is where a kitchen scale comes in really handy.  I wanted my layers to all be the same size and height and I knew that I wouldn't be able to eye it close enough.  So, after I had divided the batter between my six bowls, I then weighed each bowl and re-distributed the batter as needed, so that each bowl weighed nearly the same amount.  That way I knew each cake was going to be approximately the same size.

4.  Once your batter has been evenly divided, add a different color to each bowl.  I was using neon gel food colors so I didn't need a ton of color to reach a really vibrant color.  We went with the traditional colors... red, orange, yellow, green, blue, and purple.  Sorry my picture seems to be missing a couple colors... they must have already been in the oven baking!

5.  Once you have your rainbow assortment of batter, you're ready to bake them.  This is where multiple cake pans come in handy.  I only had two pans so I baked two colors at a time.  Once those were done, I got to set them out to cool, wash my pans and bake my next two layers.  Repeat as necessary.  Luckily, your cake layers are smaller than normal so the baking time is much shorter!  Watch them carefully.  My layers were done in 11 minutes... but that was on convection.  I recommend setting your timer for about ten minutes and then watching closely until they're done.  If you're using at least 6 six colors, they'll probably be done in under 15 minutes.

6.  Once a layer is done, turn it out to cool on cooling racks.  I sandwiched my layers between layers of wax paper.  It made it much easier the next day when it came time to stack them all together.  It gave me a nice, flat surface to stack on.  I just peeled the wax paper away from the cake.  Once all your layers are baked and cooled completely, you're ready to start putting it all together.


Filling:
1.  Mix the pudding mix with 1/2 the milk called for on the box.  Whisk until it starts to thicken.  Then fold in 1 container of cool whip.  Done.  That's it.  Set aside until you're ready to use it.


Frosting:
1.  In a small bowl, whip the whipping cream until stiff peaks begin to form;  set aside.

2.  In a large bowl, beat the cream cheese with the sugar, salt, and vanilla.  Mix until smooth.  Gently fold in the whipped cream.

Assembly:
This is where you can do whatever you want.  Some variations of the rainbow cake keep a very light sandwich filling, so the rainbow effect is stronger.  But I like filling.  Lots of it.  So I simply spread a bit of filling on my bottom layer of cake and then topped it with my next layer.  Continue this until you get to your top layer.  I tried really hard to keep it really even so that my layers stayed even but my final cake was leaning just a bit.  It's probably best to measure out the filling amount so you use the same amount between each layer, but I didn't do this and a couple of my layers were a bit thicker than others.  Oh well. 

Another option... brush some jelly or syrup on your cake layers before sandwiching them together, for more flavor.  I added some raspberry jelly to a couple of my layers, but I found that it discolored the cake just a bit, so if I do that again, I'll only brush the darker cake layers with it. 

Quite frankly, the cake looks really pretty just like that if you're careful not to make a mess with your filling.  But, I wanted to create some real drama when you cut into the cake so I wanted to cover up all the color and just present a plain white cake to the birthday boy.

Once I had all my layers sandwiched together, I did a quick crumb coat with the cream cheese frosting and put the cake in the fridge to chill for a couple hours.

Once it was nice and cold, I pulled it out and used the rest of my frosting to cover the cake completely.  Keep in mind that there is a LOT of cake in there, so don't skimp on frosting.  It needs to balance out all that cake!

I'm sure a more talented cake decorator could do something special with the white outside, but I'm lucky to get a decently smooth exterior, so I just left it like that and gave the top a quick spray of color and some sprinkles.  And then it was ready!

This was easily the biggest cake I've ever made, but it looked awesome when we cut into it and the birthday boy loved it.  And it didn't hurt that it was delicious to boot!