Crafty Makes, Food

Rainbow Unicorn Cake With M&Ms Centre


Hi, it’s been a little while but don’t worry my camera is full of all the things I have been up to- I just need to get sharing with you guys!

It was my daughters 5th birthday and she is currently loving unicorns, ponies and dinosaurs (why should dinosaurs just be for boys?? – she puts my knowledge of them to shame). Anyway… She saw a unicorn cake in a cake shop window and it was love. I knew then that that was going to be my cake challenge this year. Her past cakes have been Iggle Piggle, Mini-beasts, Disney princess and a stack of Eierkoekens covered in chocolate and sprinkles (we were in Holland – little effort but she loved it).

This post shows you how I decorated the cake. You can use your favourite vanilla sponge recipe or even use a couple of cake mixes.

Ingredients & products needed:

  • 1.5kg ready to roll icing. Really I probably used about 1kg but best to be on the safe side).
  • Wilton food colour gels (I bought a box on Amazon originally for when I made a layered rainbow cake as it doesn’t have that nasty food colour taste, but have used so many times for play dough and slime recipes).
  • M&Ms
  • Edible glitter (optional)
  • Wooden skewers for the horn and ears to stay supported on the cake.
  • A deep cake pan.
  • Butter cream – I used a ready made Betty Crocker one as I was worried my own one would go soft too quick. (1 tube for each the sponge and the unicorn hair)
  • Rolling Pin


Separate the cake mix into bowls – 1 for each colour you’re using.

1 (4)

Using a spoon, put half the mix in a cake pan in even ‘splodges’ layering the colours.

2 (4)

Then like when making a marble cake, use a pallet knife to swirl the mix around – not too much though or it will blend into one colour (like when my daughter mixes play dough and it ends up a weird brown).

3 (4)

Following the instructions on your recipe, bake both sponges. I cut or the outer cooked layer and crumbled to add to the butter cream – for extra colour.

4 (4)

Add the rainbow crumb to the buttercream and core out a hole for the M&Ms (if I made again I would have made a bigger core – but it means less cake). Cover the first sponge with the buttercream – I added some extra M&Ms as there were lots left and it stopped me eating them. Add the 2nd sponge and as evenly as possible cover with buttercream.

5 (4)

Roll out the icing and cover the sponge. Then It’s time to turn this into a unicorn!

6 (4)

I ended up adding a bit of colour in the icing before shaping (I didn’t think of that at first so made a white one originally). Roll out a long sausage shape which tapers at 1 end. Wet the wooden skewer so the icing sticks to it. Starting with the thinner end, place the icing in the end of the skewer and wrap it around so it spirals. Leave that aside to set.

7 (4)

Then cut our 2 ear shapes, then 2 smaller versions which will be the inner ear (I brushed these over with a golden yellow colour to match the horn). Use water as a glue to stick booth layers together. Leave them to set on a rolling pin – to get a rounded shape.

8 (3)

The eyes can be done in different ways, the easiest to paint or draw them on with food colour. I coloured a bit of icing black, rolled it out and cut out these eyelash shapes.  I also brushed over with edible glitter dust.

9 (3)


10 (3)

Put it all together! Insert the horn into the sponge. Gently put wooded skewers in the ears and gently push them down into the cake. Use water again as a glue for the eyes.

Annoyingly, I didn’t take photos of me piping but I’ll explain. I separated the buttercream into 3 bowls and coloured them pink, purple and blue. I only had a basic piping bag kit I picked up from Morrison’s last minute and used the biggest nozzle. You can buy the piping bags with sections to separate the colours with a good effect. All 3 colours went into the bag and I just piped away, starting with the front and made my way round and down. I then brushed over everywhere with edible glitter.


My daughter loved it and was so surprised when we cut her a slice and saw the rainbow sponge and M&Ms.


Do you think you’ll give this ago? Do you know any unicorn fans?

Please comment below.

Jaimi x

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  1. So pretty and colorful! I love rainbows AND unicorns, so I am in cake heaven! Thanks for sharing!

    1. Your very welcome Vox – thanks for commenting! 😊

  2. That looks too good to eat!! Very creative and beautiful. I know a little girl who would love that for her birthday. Unfortunately, her momma is not quite so creative!

    1. Thanks so much for the kind words Jem! I really think you could they are simple shapes – have a go! 😁

  3. I can’t believe how simple this looks and the ingredients are easy to source out!!! Definitely going to try this out, thank you for sharing!

  4. Hiiii 🙂
    I found your blog from the networking group on Facebook. It’s very delightful. I love your ducks lol.
    Nice to meet you. I look forward to reading some more xxx

    1. Hi 🙃 Thanks so much – I enjoyed reading your blog with great poetry! My ducks are funny characters -waddling around the garden eating my spinach and lettuce growing haha. I would love to get some more as ducklings – they are adorable. Nice to meet you too – great to chat to a similar minded person x

      1. Ohhh i would love one so much. My dad had them growing up.
        We have four tortoises. Two are giant ones, at full size they will be roughly 3ft lol. Xx

        1. Wow! I remember after school one day me and my friend went to the pet shop to buy a tortoise with £5 each- they were waaay out of our price range haha! 3ft is crazy but cool x

          1. Haha. They used to be just 50p each in crates at the market when my mum was young. Now they see hundreds. Madness xx

  5. HayHayLA says:

    Wow this cake is GORGEOUS!! You have an amazing talent. Thanks for sharing!

    1. Thanks – it went down well with only a few rainbow crumbs left haha 😊

  6. Brittany says:

    Cute! My kids would love this!! Thanks for a great tutorial!

    1. You’re welcome Brittany 😊

  7. So pretty and colorful 🙂

    1. Thanks Muhammad! It was a fun one to make.😊

  8. I love this cake!!! Maybe someday my baking skills will be good enough to pull this off. Thank you for sharing!

    1. Go for it Amy! You can even use a cake mix – the rest is more like playing with modelling clay than baking.

  9. Love this cake! You did a great job on it !

    1. Aww thanks – it really was fun to make.

  10. Omg this is amazing! I don’t know if i’m brave enough to try though.

    1. Always be brave enough to try anything! Worst case scenario it will be a colourful and edible still haha. 😊

  11. Amazing! It not only looks beautiful, it sounds delicious!! I love how the steps you give are well explained and easy to follow. Great post! 😀

    1. Thanks Carolina – I try my best to keep it simple 😊

  12. helenevlacho says:

    So colorful and so cute! The best cake for kids!

    1. Thanks Helen – my daughter loved it!

  13. I love this! I wish I could make this but I have no one to make it for lol.

  14. Yes, I know a unicorn fan: me! I’m having a little girl and I want to make my baby shower unicorn themed. I agree that dinosaurs shouldn’t be just for boys, what nonsense! That is how society stops girls from pursuing careers in non-traditional fields. I say no! Dinosaurs are for whoever like them!

  15. This is a beautiful cake with great instructions. I don’t know what little girl who wouldn’t love to get this cake on her birthday!

  16. You have one lucky little girl! That cake is amazing and looks delicious!

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