Rainbow Layer Cake

We have been celebrating our daughter's birthday and I surprised her with a Rainbow Layer Cake which I am just so pleased with.  I've seen these cakes before and seeing that our daughter loves bright colours I thought this the perfect cake for her.

As this was my very first time I did quite a lot of research and checked many recipes before finally settling on one.  I picked up a few tips from various websites and put them into practice with good results.

This recipe makes six slim cakes which are layered on top of each other with buttercream.  To ensure you have flat cakes these Bake Even Strips work perfectly.  The cakes I made were all level which made layering so much easier.

There were also a few ideas I found which really helped to enhance the colours and make them vibrant.  I purchased three food colouring gels in red, blue and yellow.  Three of the layers were primary colours and for the other three I mixed two primary colours together.  The gels are vibrant, easy to control and you don't need to use a lot so the consistency is not affected.

Another tip I discovered with rainbow cakes is to leave the vanilla extract out of the mix.  To gain lovely vibrant colours you need to start with a very light coloured cake mix.  The vanilla may change the colour just a little.

I also purchased the eggs instead of using our own.  Reason being is that our eggs have lovely big yellow yolks however I was looking for a light coloured cake.  The eggs from the supermarket have lighter coloured yolks.

These may be small things however put together they do make a difference.  Being our daughter's birthday cake I did all I could to make it just right.

I also made the cakes during the week and froze them.  The day before I removed them from the freezer to defrost.  In the morning all I had to do was add the buttercream and decorations.

Individually wrapped ready for the freezer.

375g unsalted butter, softened
675g plain flour, sifted
450g caster sugar
9 eggs, room temperature
3 teaspoons baking powder, sifted
3/4 teaspoon salt
Red, blue and yellow food colouring gels

350g unsalted butter - take out of the fridge to soften
700g icing sugar, sifted
2 teaspoons vanilla extract

Preheat the oven to 180°C (160°C fan-forced).  Grease two round cake tins and line the bases with baking paper.  Make sure the sides are also greased.  I used two round sponge tins.

The cakes are made up in three lots therefore the ingredients are split three ways.  You make two cakes at once using the following measurements.  

Place 125g butter, 225g plain flour, 150g caster sugar, 3 eggs, 1 teaspoon baking powder and ¼ teaspoon salt into the bowl of an electric mixer.  Beat well until smooth.

Next you need to split the batter into two equal portions.  Place onto the scales and halve by placing into two bowls.

First mixture ready to be divided into two.

Add your chosen colours to each bowl and mix until you reach a colour you are happy with.  Place batters into the two prepared cake tins.

Ready for the oven.

Bake for 12 minutes or until a skewer comes out clean.

Remove from the oven and let cool for 10 minutes in pans before very carefully turning onto a wire rack to cool completely.

That's two cakes down.  Now repeat this process two more times to make a total of six cakes.  

You can either freeze the cakes now or continue onto assembling with the buttercream.

To make the buttercream beat the butter and icing sugar until light and fluffy.  Add the vanilla extract and beat.

Now for the fun part of assembling and decorating.

Spread a small amount of buttercream onto a cake board.  I covered a thin baking tray with foil.  Place the first cake layer onto the buttercream.  Spread a thin even layer of buttercream over the cake.  Top with another cake layer.

Two more layers to go.

Repeat until all cakes have been sandwiched together.

Cover the top and sides with the buttercream.  I then used a sheet of paper towel to dab around the cake to smooth the buttercream a little.

Now for the messy part.  I decorated the top and sides with 100's and 1000's.  I covered the sides by placing small amounts of 100's and 1000's into my hand and pressing onto the cake.  Little by little I worked around the cake to cover as best I could. 

Time for the big moment of slicing and exposing those lovely bright colours.  I was just so happy when it sliced perfectly and the layers were exactly how I wanted them.  We had a very happy birthday girl.

The steps for this cake were very easy to understand with a great result.  I'm so proud of this cake and best part of all was the look on our daughter's face.  She loved it so much and I'm sure it will be one she will always remember.

Happy Birthday lovely girl xx.



  1. That is a very impressive birthday cake. You have outdone yourself. I'm afraid if your kids go to eat at other family's houses they may be in for a rude awakening. Just kidding...

    1. I was holding my breath while she was cutting it. Fingers were crossed the layers had worked. I almost couldn't look.

  2. Happy Birthday to your daughter Kylie! 🎁🎉🎈How special for her and I'm sure it meant even more because you made it. What a great job you did. I made a round cake for my daughters birthday and was going to sprinkle hundreds and thousands on the sides. I read a tip that said spray baking paper with oil. Put the sprinkles on the baking paper where they will stick, then press that into the sides of the cake. I didn't end up trying it but it sounded like a good tip! Hope the birthday girl had a great day.

    1. I had read about that tip too Belinda however I don't have the cooking oil spray. From what I read it's very successful.
      I've passed on your birthday wishes to our daughter - thank you.

  3. Brilliant cake. Love all the colours. Well done. Happy Birthday to your daughter.
    Cheers, Jo

    1. Thanks Jo. She had a brilliant day

  4. Oh how wonderful, she'll always remember this special cake made with your love xxx

    1. Thanks Sue. I think it's special things like this that we remember and cherish.

  5. Kylie that is one impressive cake!

    1. I'm just so pleased with how it turned out and loved making it for her knowing how much she would love it.

  6. What a special cake! I'm sure all the time and effort you put into making it for your daughter was worth it when she cut it and saw those pretty rainbow layers. Amazing! Meg:)

    1. Oh Meg it was all worth it. Birthdays are just so memorable and each year the kids say 'that was the best Birthday ever.'

  7. I would have been so excited to have a cake like that when I was a girl. Well done on a beautiful cake.

    1. Thankyou so much. I just love doing things like that for the kids and seeing their joy. They're always so appreciative too and let you know.


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