Rainbow Cake

This cake has been taunting me for over a year. I think it's been about that long since the rainbow cake took over the cake world (kinda like how cupcakes did some years ago). It seemed like everywhere I looked I was confronted with them: at parties, in magazines, in blogs ... everywhere. Told you, the cake was taunting me.

To be honest, I love the look of the rainbow cake. Even though it has blue and purple layers; green even -- I mean who eats blue cake? But it's a pretty cake. Who isn't cheered by a rainbow, right? Yup, the cake is a show stopper, no doubt about it.

I resisted making one until now for several reasons.

First of all it looks like it entails a whole lot of work. Also, the amount of food colouring required to create the bright, colourful layers is frightening. To top it all, seven layers of cake makes for a mighty large cake and in a house of two people and a dog that has been put on a diet, this cake could well last forever!

But when a friend gave me a set of all-natural food colouring some weeks ago, I buckled and got down to making my first (and probably last -- but more on why later) rainbow layered cake.




Was it a lot of work? Well, yeah. For six layers of cake (yeah, mine is not quite a full rainbow), I had to make two batches of my favourite vanilla cake recipe. And, two batches of frosting too.

The batter had to be divided into six equal portions and then coloured: I only had the four primary colours (red, yellow, green and blue) and so I had to mix them to get the shades of orange, purple and aqua. That part was fun.

When that was done, each individual layer had to be baked separately for 20 mins or so each. (Mine is a small oven and so baking two 8-inch cakes at a go was not an option).

Then, the multiple layers had to be chilled (to make it easier to frost and stack).

Next comes the stacking: each layer had a thin coat of frosting on top before the next layer is stacked on it. Most bakers use Swiss meringue frosting but I used plain butter cream.

Finally, the entire cake is coated with the same frosting. If you're thinking that's a whole lot of frosting, you're spot on. Sweet doesn't begin to describe this monster of a cake (all done, it measured about 8 inches and I needed a bread knife to cut through the layers!).



All in all, the cake was beautiful once done. I was happy with my effort and could not wait to photograph it ..... photographing takes precedence over eating it even! Unfortunately, my camera chose this day to malfunction. The shutter jammed up for some reason and I had to resort to my phone camera to capture these images, hence the less than mediocre images. Sigh.

Why universe, why???

Nevertheless, the cake tasted delicious. It's a vanilla butter cake recipe which I've made before: you can get the recipe here.

Equipment needed
Two or more identical sized 8-inch baking tins, round or square is up to you
food colouring/gels in red, blue, green and yellow

Rainbow cake
1. Mix batter for Butter Cake  (make two batches)

2. Divide the batter (both batches) into six or seven equal portions (the amount is enough for seven thin layers or six slightly thicker ones. I'd go for seven as thin layers are easier to eat!)

3. Add the colouring for each batch.
    For the deep purple, you need 1 drop of blue for every 3 drops of red. (You'll need to multiply this at
    least by 6 to get a vivid purple).
    For the orchid/light purple layer mix 1 drop of blue for every 4 drops of red.
    For the orange, mix 1 drop red for every 2 drops of yellow.
    For the Aqua, mix 2 drops green for every 4 drops of blue.

4. Line and grease the baking pans. Bake each layer for about 20 mins in a preheated oven (170C) or until a tester comes out clean.

5. Let the layers cool once they are out of the oven and then chill them for at least an hour.

6. Once chilled, lay the deep purple layer on your cake board first. Spread a thin later of butter cream icing (recipe below) and stack the light purple layer on top. Frost again, lightly and then follow with the blue, green yellow and finally orange layer. Once the final layer is on top, chill the cake again for 30 mins before icing the entire cake.

7. Chill before cutting.

Butter cream frosting (enough for layers and to cover the cake)
[If you have a large mixer, you can make two batches of this recipe together]

360g butter, softened
840g icing sugar, sifted
50 ml milk
1 tbsp meringue powder (optional)
2 tsp vanilla extract

Cream butter till light. Add sifted sugar and gradually and the meringue powder and mix on high speed until fluffy, about 3 mins. Add the milk and extract and mix for a further 5 mins until the frosting is almost white and very light.