Rainbow cake is one of those things that I’d always wanted to try my hand at but was too daunted by the idea of baking a million cakes and dyeing them and assembling them. But something about the new year and a Sunday with nothing to do spurred me to finally give it a go! And yes it did take ages (a seasoned baker could probably do this in 2 hours but it took me 4…), but the results were amazing and who doesn’t love a colorful rainbow cake?
Before we begin, this cake does require some preparation, but I found a few neat tricks to make the process a little easier that I’d love to share with you.
Firstly, a rainbow cake requires baking 5-7 cakes in order to create the most beautiful layers. 5 layers is really the bare minimum I think. I did 6 because it was easier to divide the batter that way, but the sky’s the limit! Instead of buying 6 expensive cake tins, I used disposable 7 inch round foil trays to bake my cakes. I think the difference a real cake tin and a foil tray makes in the case of such thin cakes is marginal, so I highly suggest using foil trays instead! Six 7-inch layers combined makes quite a small but tall cake. If I were to do this again I’d probably use 8 inch foil trays instead.
Next up is the coloring. Regular food coloring that you find in the supermarket aisle simply won’t cut it in this case. To get such vibrant colors you have to use either a paste or a gel coloring. I used a brand called Americolor which comes in small tubes of gel, but I’ve been told that Wilton Color works even better as it’s a paste. You can just buy 3 primary colors (red, blue and yellow) and mix them to get more colors, but I’m lazy and didn’t want to risk some crazy color mixing mishap, so I just bought the 6 colors I wanted to use, which in Americolor terms is Super Red, Orange, Egg Yellow, Forest Green, Royal Blue and Regal Purple. Keep in mind that an Ombre Cake can also be achieved using this same technique with just one color in varying doses if you prefer doing that!
Now for the icing, you must must MUST allow the cakes to cool fully. and I do mean room temperature, zero bit of warmth fully before you ice! And you don’t have to use my icing recipe at all, any type of thick icing will do. But it has to be very thick in order to hold the layers together.
Finally, onto the cake!
350g self raising flour
350g melted butter
350g caster sugar
1 tablespoon vanilla extract
Food colorings of your choice
1 tsp vanilla extract
750g of cream cheese
350g icing sugar
1. Mix first 6 ingredients for the cake batter together, it should form a fairly thick cake batter as we want thin cake layers that don’t rise too much. Preheat oven to 175 degrees celsius while you’re at it.
2. Seperate batter into 6 seperate mixing bowls. Or in my case I used disposable foil trays to make clean up easier. Each bowl/tray should contain about 1 cup of batter.
3. Now color the six batters. Whatever coloring you’re using, start with a little at a time. Remember you can always add more but it’ll be a pain to remake more batter! I used chopsticks to mix mine just to make clean up easier
4. Pour each batter into it’s cake tin/foil tray. It’d obviously be ideal to bake all 6 at one go, but it’s perfectly fine to do them in batches depending on how many cake tins you have. They should bake for around 20 minutes. Stick a chopstick/toothpick in to check, and if it comes out clean, the cake is done.
5. Once the cakes are done, remove them from the oven and place on a cooling rack to cool for as long as it takes for them to reach room temperature. Can’t stress this step enough! Expect to wait about 30 minutes – have a glass of wine and take a much deserved break now!
6. While the cakes are cooling, mix all the icing ingredients up to create a nice thick icing.
7. Once the cakes are cool, use a serrated knife to cut off the rounded top layers to make the top side even. The cakes should be about 2cm thick.
8. Now onto frosting the cake! Start with the purple layer (in order of a rainbow). Place a small dollop of icing onto the plate first before putting on the first layer to make sure it doesn’t move around. Ice the top of each layer thickly all the way to the edge, it’s ok if it oozes out as we’ll be frosting the sides anyway. Then onto the blue, green and so on all the way to the red.
9. Frost away in any format you like, covering all the sides and the top! While you’re frosting, keep cleaning your spatula as you go as crumbs will collect on the icing and we want to keep it as white as possible! Don’t worry about keeping the icing too smooth as the crevices and waves actually make for quite a pretty effect!
10. Finally, throw on some sprinkles to the top/sides, decorate as you please, then cut into this magical creation and let the ooh and aahs begin! Rainbow cake = a slice of Happiness don’t you think?