First of all, this is the most beautiful cake ever! I saw the rainbow cake on Pinterest (of course!) and I knew I had to give it a try. I made it for my mom's birthday and everyone was impressed! I do think you should read all the tips several times before making the cake though. I think I read through the original recipe tips/comments/etc probably 5 times prior to making this cake. I really didn't want to mess it up! I'm listing the most important ones below.
A few things:
- The original recipe uses cake mix with Sprite Zero instead of oil, water, and eggs. I'm sure that would still taste delicious, but I went for regular cake with all the normal ingredients. So if you want to use Sprite Zero with your cake mix, look at the original recipe.
- This is why in my pictures (compared to the original recipe) the batter is much thinner. The Sprite Zero gives you a thicker, lumpier batter.
- Make sure to buy the Betty Crocker Gel Food Coloring. The gel is more vibrant, and you don't have to use as much! In my Kroger, it wasn't with the other food coloring. They had it with the cupcake liners, candles, cookie frosting, etc. It comes with red, blue, green, and yellow. I just mixed colors to make the purple and orange.
- The original recipe used a frosting made from Cool Whip and pudding. I just bought Betty Crocker Whipped White Frosting (2 containers).
- I recommend checking out the original recipe for excellent step-by-step pictures! Also, the girl is hilarious, and you'll probably get a kick out of reading her post/directions.
2 boxes white cake mix (I used Betty Crocker White Super Moist)
6 eggs, 2 1/2 c water, 1/2 c oil (unless you're using Sprite Zero)
Gel food coloring
frosting (you can use whatever kind you want!)
1) First, make your cake mix according to the package directions. Then, spoon about 1 1/2 cups of batter into 6 different bowls and add your food coloring, blending well.
2) Now, spray your cake pans well. I used two 9" round pans. In the first pan, you're going to put red, orange, then yellow. But it's important that you use about 2/3 of the total batter for the first color in the pan - in this case, red. Otherwise, your last color you put on top will dominate the cake.
3) So get your red, and pour about 2/3 of the total batter into your pan. Make sure you pour it in the middle. You should just start to get pretty geometric circles of batter. Then get your orange, and pour that right into the middle of the big red circle. Pour about a cup of the orange, but I just estimated. Then, get your yellow and pour about another cup of that right into the middle of the orange circle.
4) Now, you're going to switch to your second pan to use the other 3 colors. According to the original recipe, this is so your two cakes end up being the same size. So now, just like you did with the red, pour about 2/3 of the total purple batter into the second pan. Then get your blue, and pour about a cup of that into the middle of the purple circle. Next comes green, which should be poured (about a cup of it) into the middle of the blue circle. Now your two pans look very pretty... but they're about to get even prettier!
5) Ok, now go back to your pan with the red, orange, and yellow - you're going to finish it up. Pour your green into the middle of the yellow circle. I did end up with a little batter left over in each of my 6 bowls... just because I was being careful. Then, pour your blue into the middle of the green circle, and then your purple in the middle of the green circle. Done with that pan! It will look beautiful.
6) Next pan! Finish it up by pouring your yellow into the middle of the green, then orange into the middle of the yellow, and last your red into the middle of the orange circle. Look at how awesome they will look!
7) Amazing!! Time to bake them now. Bake according to your package directions. I think mine was 350 degrees for 30-35 minutes. Of course they're done when you insert a toothpick into the middle and it comes out clean. Let them cool a while in the pans. Then, carefully remove the cakes and let them cool on a wire rack.
8) Once completely cool, go ahead and assemble and frost your cake. It will be VERY hard waiting to cut into it... but definitely worth the wait! Everyone will be amazed. Enjoy your super awesome cake.
Original recipe found here.