Today, let's make a rainbow cake!!

Everyone has seen pictures of these and thought, "I should make that sometime," but they never get the opportunity. My sister's birthday was quickly approaching as I set out to fulfill the demand for this sweet, buttery, color-themed birthday/party/anytime cake. Here's your opportunity. You're welcome.

It's actually very simple to make compared to the results, and no super special equipment is needed. All you need is:

The batter for one white cake, at least a three-layer recipe, and the ingredients to make it. (I used "The Best White Cake Recipe {Ever}" from Add a Pinch: http://addapinch.com/cooking/the-best-white-cake-r... )

Food coloring in the colors of the rainbow. (I found gel coloring in tubes and then neon purple in liquid form).

A double-batch of your favorite frosting. (I used the "Classic White Buttercream Frosting Recipe" also suggested by Add A Pinch: http://addapinch.com/cooking/classic-vanilla-butte... )

Six 8" disposable pans (or adjust the size according to your cake recipe). They don't have to be disposable if you happen to have six identical cake pans on hand, but..

The whole process is made easier and probably faster with a stand mixer, but that's only if you are going the from-scratch route. Two box mixes and cans of frosting would work just as well if you're looking to save time.

Step 1: Color the Batter!

Firstly, you need to find a cake and frosting recipe or purchase box mixes.

Done. Then you make the batter according to the instructions.

Good. Next you distribute it evenly into six bowls.

Wow, you're good at this. Now color them.

Wait! Easier said than done-- how exactly do you get the right shades?

You can do whatever colors you want, but I chose a full rainbow. Red, yellow, green, and blue are all pretty easy. I had to use about a half tube for each in order to get the brightest coloring, but it will vary by what type of food coloring you have. To make orange you need about a 6:2 ratio of yellow to red, which meant for me that I squeezed the yellow for three seconds and the red for one. It mixed into a perfect shade that I didn't want to mess with after.

Purple can be tricky to mix due to both blue and red being dark colors-- it's easy to end up with gray. Yuck. A 3:2 ratio of red to blue should do the trick, or use purple gel or liquid food coloring, which can be found in neon packs or specialty stores. Beautiful!

Step 2: Bake the Cake!

Let me introduce you to my good old friend, Pam. In order to succeed in this step, you're going to need a ton of it.

Nonstick spray or butter is essential for this delicate cake, so spray like there's no tomorrow. In the bottom and on the sides. A dusting of flour on the bottom of the pans wouldn't hurt either, nor will buying pans that aren't ribbed on the edges.

Yes, I did have some trouble with the cakes sticking. They were thin cake layers. There was not enough spray. I ended up cutting the sides of each pan and using a spatula to coax the cakes onto paper plates. Whatever. It was messy but overall effective.

Pour each color in a separate pan, or swirl colors together to make it groovy! Spread the batter out towards the sides-- you want it to be as even and flatas possible for layering.

To bake, I placed the pans in staggered positions in the oven, as shown. If your oven is not big enough for this, you could bake them in batches. My cakes took about twenty minutes at 350. They had a pretty even crust, but you could rotate the pans halfway through cooking if you'd like.

Step 3: Assemble!

After they have cooled, you can assemble the cake layers on a plate, tray, or stand. I happen to have a handy cake carrier.

Don't forget about the frosting. It can be buttercream, marshmallow, white chocolate, or cream cheese, and any color you want to dye it.

If you are making it homemade, I would try to use a little more milk to make it thinner so that it is easier to spread. The layers can be delicate at times.

If you are using cans of frosting, you will need at least two. I would stir them well and maybe even warm the frosting in a bowl in the microwave for about ten seconds to make it go on smoother.

Starting with purple, layer a cake and then spread a medium-thin layer of frosting. Repeat, in reverse-rainbow order, and then use the rest of the frosting to cover the cake. You could make the outside look like sky or clouds; I worked with Robot Dinosaurs in Space as the theme, by request ;)

Step 4: Decorate and Serve!

Everything involved in making this cake is worth it when you see people's reactions to it!

Though the best view is the inside, you can make the outside look however you want.

As I said, my goal was to make a cake that looked like dinosaurs in space. This was as close as I could get.

I cut out the frosting with a cookie cutter in the middle of the cake. I would imagine you could do the same thing with any shape on the sides of the cake to give it sneak-peak rainbow window. I actually did it because my so-called "handy" cake carrier attached to and pulled off the top middle of my cake! The decoration was a sort of repair job.

After letting it sit out from the fridge for about a half hour (chilled buttercream is rock-hard), I colored the frosting. I dripped blue and teal food coloring on the sides and swirled it in before adding some intergalactic silver candles and adorable dinos in (sort of) the shape of a star.

And of course, the cake was delicious. I think it may just be the {best} not-so-white cake ever. Don't believe it? Just ask the 3 1/2 cups of butter involved!

I'm glad to report that my sister loved it. Happy Birthday and happy cake-making!!