Rainbow Cupcakes!

  • Claire OBeirne
  • Jul 10, 2020

Hi everyone!  I'm super excited to introduce Sarah from A Spoonful of Vanilla onto today's guest blog.  Sarah has amazing recipes on her blog, and after test driving these rainbow cupcakes yesterday - 100% can vouch that they are DELICIOUS.  In fairness to her recipe, the photos uploaded are from my creation and I turned them into mermaid themed cupcakes. My icing and rainbow didn't look quite as pretty, so I'll add in a couple of her examples at the end to what they should look like!



Rainbow Cupcakes

Vanilla rainbow cupcakes, with vanilla buttercream and of course rainbow sprinkles!


Rainbow Cupcake Example 2

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Ever since I made my Rainbow Cake I have wanted to make the cupcake version. So when Claire came to me saying she had an opening on her blog for a recipe and she wanted me to make something colourful and fun I knew I had to make these cupcakes.


To make these cupcakes I used a similar method to my Velvety Vanilla Cupcakes. I did increase the amount of ingredients I used so I dye the batter into my rainbow colours, as I was worried I wouldn’t have enough batter.


To make the cupcakes I start off by mixing my butter and caster sugar together until the butter is soft and lighter in colour.


Next I add in the flour, eggs, baking powder and vanilla extract and mix again until all the ingredients are combined. Next you want to split the mixture into five separate bowls. I used five colours rather than seven just because I didn’t think I would have enough mixture to get even layers of rainbow if I used seven colours so I used five so I could get thicker layers of colour.


I used Pro Gel food colouring. I would recommend using a gel based food colouring for these as you only need a tiny bit to get really vibrant colours. I have found if you use water based food colouring you need to add more to get the colour you want and they can often have a horrid aftertaste.



For the buttercream I decided to use a simple white buttercream. I thought because the cupcakes were rainbow that rainbow buttercream might be too much. In a bowl, I mixed together the icing sugar, butter and vanilla extract. If you find your buttercream is too thick add 1tbsp of milk at a time mixing in between until it reaches the desired consistency.


For the buttercream you need to use unsalted butter, if you use a baking spread or stork you will find that it is too soft. If you want to make rainbow buttercream check out my alternatives section below for the instructions.


Pop the buttercream into your piping bag, I used a Wilton 1M Piping Tip and pipe the buttercream on top of your cake. I decorated it with the prettiest rainbow sprinkles from Sweetapolita.


rainbow cupcakes example 1

What equipment do I use?


  • Cupcake Cases – I used rainbow cupcake cases from Dr Oetker. They come in a pack of six colours and I used 2 colours from each pack. They are also quite deep cupcake cases which means even more cake! YAY!
  • Spatula – I will always use a spatula over a wooden spoon. Spatulas will be able to get any left-over batter from around the sides of the bowl.
  • Scales – If you don’t use scales to weigh your ingredients you are essentially setting yourself up to fail. So many things can go wrong if you use too much flour or sugar in recipes.
  • Piping Tip – I used this large round piping tip to pipe the buttercream.
  • Piping Bag – I use these large savoy piping bags.

What ingredients do I use?


  • Self-Raising Flour – I use a supermarket own brand.
  • Caster Sugar – I use Silver Spoon sugar
  • Butter – For the cupcakes I use a baking spread or Stork. For the buttercream you must use unsalted butter or your buttercream will be too soft.
  • Vanilla Extract – I used Dr Oetker
  • Baking Powder – I used Dr Oetker
  • Food colouring – I used Pro Gel Food colouring
  • Icing Sugar – I used Silver Spoon
  • Sprinkles -  I used the Party Classic Non-Pareils from Sweetapolita



If you want to make rainbow buttercream, split your buttercream into five different bowls and dye with food colouring. Next set on a piece of cling film flat on the kitchen worktop. You can either spread or pipe each individual colour onto the cling film and roll it up into the cling film. Secure both ends and then you want to cut one of the ends off and pop it into the piping bag. Now when you pipe the buttercream it will look just like a rainbow.

Rainbow Cupcakes Example 10


Shopping list

For the Cupcakes

  • 200g Unsalted butter or baking spread,
  • 200g Caster Sugar
  • 200g Self-Raising Flour
  • 4 Large Eggs
  • 1tsp Baking Powder
  • 1tsp Vanilla Extract
  • Gel Food Colouring


For the Buttercream

  • 500g Icing Sugar
  • 250g Unsalted Butter
  • 1tsp Vanilla Extract
  • 2-3tbsp Whole Milk



To Make the Cupcakes

  1. Preheat the oven to 180C/160 Fan. Line a muffin tray with cupcake liners and leave to one side.
  2. In a large bowl, whisk together the sugar and butter until light and fluffy.
  3. Add in the flour, eggs, baking powder and vanilla and whisk until all combined.
  4. Split the mixture into five bowls one of the bowls and dye the batter in each bowl with a different colour.
  5. Spoon the mixture into the cupcake liners. It is completely up to you how you add the mixture you can either layer it or marble it, and then pop them into the oven to bake for 15-20 minutes. You will know the cupcakes are ready when they are golden and spring back when you touch them.
  6. Leave to cool.


To Make the Buttercream

  1. In a bowl mix together your icing sugar, butter and vanilla until it is nice and smooth. If the mixture it too thick add 1tbsp of milk at a time stirring in between until it reaches the desired consistency.
  2. Pop the buttercream into your piping bag and decorate. I piped simple swirls on my cupcakes using my 1M Piping Tip and I decorated with some pretty rainbow sprinkles.

(what they're supposed to look like!)


You can follow Sarah on:

Her Website Twitter | Instagram


Wrap up time!


A massive thank you again to Sarah for her amazing recipe.  These were a great hit at home, and nearly all of my batch has been demolished!  Are you keen to try them out? Let me know in the comments!  As always, if you'd like to appear on the blog with a guest post - feel free to send me a suggestion on my contact page. 

I hope to hear from you soon!




  1. Nic | Nic's Adventures & Bakes

    August 14, 2020

    Thanks for sharing, these look amazing and yummy 🙂

    Nic | Nic’s Adventures & Bakes

  2. Love, Em

    July 13, 2020

    These looks so delicious!! I love cupcakes – anything cake and you’ve won me over! I think a Spoonful’s recipes are always so amazing, it’s the reason I can’t stick to a diet! I do so well then BAM cake! and I’m not complaining! Thanks for sharing – these look so amazing!

    Em | http://www.loveemblog.com

  3. Serena

    July 13, 2020

    These look so yummy! I love rainbow cakes and the mermaid tails make these so fun!

  4. Laura

    July 11, 2020

    These look so yummy, I’m happy to finally have a recipe for rainbow cupcakes!

    – Laura | https://lauraorvokki.com

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