Birthdays / Recipes

Recipe: Three Colour Rainbow Cake


Be under no illusion from the title that the cake I have made contains the colours (or variety of) red, orange, yellow, green, blue, indigo or violet). This cake was made for my mum’s birthday, which was last Friday, and I wanted to bake for her a cake that was a little different from the standard vanilla we are all so used to. So, I took the idea for rainbow cake and changed it up just a little. Rather than a five to seven layer cake I decided on a three layer, just big enough for everyone to enjoy without feeling too over-indulgent. And I thought I’d change the colours a little and go for a green, a pink and a blue. Why do the same as everyone else when you can do something a little differently, eh? So, this is what I created. I slightly modified the Magnolia Bakery recipe for the Vanilla Cake and made slight alterations to the Food Network’s Vanilla Buttercream Frosting to top the creation, so take a look and see if you get inspired to make your own sort-of rainbow cake for someone special in your life.

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Rainbow Cake 1

230g / 1 cup unsalted butter, room temperature

400g / 2 cups granulated sugar

4 large eggs, room temperature

180g / 1 ½ cups self raising flour

150g / 1 ¼ cups plain flour

240ml / 1 cup whole milk

1 teaspoon vanilla



1.) Preheat oven to 350°F / 180°C / 160°C fan.

2.) Measure the weight of your mixing bowl before adding any ingredients. Yes, this seems like a strange step, but it will help you later when you’re dividing your batter for your different colours. Note this weight down so you don’t forget it.

Rainbow Cake 2

3.) Grease and lightly flour three 9 inch round cake pans, then line the bottoms with waxed paper (I only had two pans, so I alternated).

Rainbow Cake 3

4.) In a large bowl, on the medium speed of an electric mixer, cream the butter until smooth.

5.) Add the sugar gradually and beat until fluffy, about 3 minutes.

Rainbow Cake 4

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6.) Add the eggs one at a time, beating well after each addition.

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7.) Combine the flours and add in four parts, alternating with the milk and the vanilla extract, beating well after each addition.

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8.) Scrape down the sides of the bowl to ensure all parts are mixed adequately.

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9.) Now you need to divide the batter into three equal parts. The easiest way I found to do this was to weigh the measuring bowl now that it is full of batter. Remember the bowl weight you noted down earlier? Now take that weight away from the total weight now. This will give you the weight of the batter, minus the bowl. Divide this number by three to get the amount of batter needs to go into each cake tin. Now get a separate medium sized bowl and pop it onto the scales – I use electronic scales, so it’s easy to reset the scales to zero once the bowl is on there. You will then pour into that bowl a third of the batter, as calculated accurately.

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10.) Once you’ve done this add tiny amount of one of your gel colours to the batter using the end of a teaspoon – I found this gave me just the right amount – mixing well until all the colour is saturated. If the colour isn’t vibrant enough for you, add a little more until you get the desired result, but this should be plenty. Once coloured, pour this batter into one of the cake tins.

11.) Bake for 18 to 25 minutes or until a cake tester inserted into center of cake comes out clean. This will vary greatly depending on your cooking appliance. I used a fan assisted oven and it only took around 18 minutes for the cake to cook properly, so check it at the earliest time and cook for longer if required.

12.) Let cakes cool in the pans for 10 minutes.

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13.) Remove from pans and cool completely on wire rack.

14.) Repeat steps 9-13 with the rest of the batter until you have three cooled layers of cake, all in different colours.

The next stage is the frosting, which is a super simple recipe, and goes a little something like this:

15.) In a standing mixer fitted with a whisk, mix together 3 cups / 340g of icing /confectioners’ sugar and 230g / 1 cup of unsalted butter at room temperature. Mix on low speed until well blended and then increase speed to medium and beat for another 3 minutes. Add 1 teaspoon of vanilla extract and 1 tablespoon of double cream and continue to beat on medium speed for 1 minute more, adding more cream if needed for spreading consistency.

Now comes the construction! If you want to, you can tidy up the cake layers by cutting around the border slightly, to reveal more of the colour instead of the slightly golden brown edge. I did this, but it is entirely your choice.

16.) Put your first layer onto a solid base (I chose green for the bottom).

17.) Spread an even layer of frosting on top of this layer, about half a centimetre to a centimetre thick.

18.) Place your next layer of cake on top carefully, lightly pushing down to compress the layers slightly.

19.) Spread more frosting on top, add the third layer and frost again.

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20.) I added frosting to the sides of the cake too, just to hide the rainbow surprise, but you can have it on display if you like. I also added a bit of sugar glitter to the top, to give a little bit of a different texture, but you can decorate the top of your cake just about however you like.

Original Recipe Credits: Vanilla Cake & Vanilla Buttercream Frosting.

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