I have always wanted to make a Rainbow Cake and I decided that my birthday this year was the perfect occasion! Instead of vanilla flavour, I went for a Lemon Rainbow Cake because it's such a large cake I thought it would be too sweet to do the whole thing vanilla. The lemon zest in the sponge and the lemon curd between each layer cut perfectly through the sweetness so it's not overwhelmingly sweet to enjoy a slice of this Lemon Rainbow Cake. Of course if vanilla is your thing, then you can easily make this cake a vanilla Rainbow Cake too!
How to make Lemon Rainbow Cake...
I own three 8" cake tins so I did three layers of the cake at a time, I started by creaming the butter and sugar together with the lemon zest.
Then I added the eggs and self raising flour, and split the mixture between three bowls.
I mixed in the food colouring, divided the mixture between the tins, then baked them.
After washing the tins, I did the same again for the other three colours.
To make the buttercream I mixed together the butter, icing sugar and some vanilla extract.
Between each layer I spread a thin layer of buttercream, then drizzled some lemon curd over the top.
Once the sponges were all stacked and filled with buttercream and lemon curd, I covered the whole cake in a thin crumb coat of buttercream. It then went in the fridge for an hour to firm up.
I spread on a final layer of buttercream and smoothed it out. Usually I would do this on a turn table, but as I was adding sprinkles to the bottom I wasn't too concerned about absolute neatness!
My family and friends loved this Lemon Rainbow Cake, and it was very popular at my birthday party. It even did well against my favourite cake of all time which was also on offer - Chocolate Guinness Cake with Baileys Buttercream!
You get quite a large slice of the Lemon Rainbow Cake even if you cut quite a thin slice, purely because of the height of the cake. But the lemon curd and lemon zest in the sponge stop it from being too sweet, which is exactly what I wanted.
What lemon curd should you use?
If you are using a shop bought lemon curd, make sure to get a good quality one. They are worth the extra pennies for that delicious lemon zing! If you fancy giving Homemade Lemon Curd a try, check out my recipe. It's easy and quick to make with only a few ingredients, it's also creamy and silky smooth, and the flavour is incredible!
Recommended equipment & ingredients*
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More rainbow recipes...
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| Rainbow Cupcakes |
More lemon recipes...
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| Lemon Meringue Cupcakes | Triple Lemon Cake | Lemon Cupcakes with Lemon Curd Filling |
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| Lemon Curd Cheesecake | Lemon Curd & White Chocolate Bread Rolls | Lemon Meringue Dessert Pots |
Ingredients
For the sponges
- 550 g Butter or baking spread
- 550 g Caster sugar
- 4 Lemons zest only
- 10 Eggs large
- 550 g Self raising flour
- 2 tbsp Milk
- Red, yellow, orange, green, blue and purple food colouring I used Rainbow Dust Pro Gel
For the buttercream and filling
- 600 g Butter or baking spread
- 1.2 kg Icing sugar
- 2 tsp Vanilla extract
- 275 g Lemon curd good quality shop bought or homemade
For decoration
- Rainbow sprinkles
Instructions
- I own three 8" cake tins so I did three layers of the cake at a time. Only make as much mixture as you have cake tins for as you must not leave cake batter sat for a long period of time as it will affect the final result. You can also buy disposable foil cake tins if you don't want to invest in more cake tins, but I recommend having at least three of the same size as there are lots of cake recipes on my blog that require three 8" tins!
- Pre-heat your oven to 160C Fan/180C/350F/Gas Mark 4, and grease and line your 8" cake tins
- Make the first three sponges by mixing half of the butter and caster sugar in a large bowl with a spoon until fluffy, or mix using an electric mixer
- Add half of the eggs, milk and lemon zest, and whisk until fully incorporated
- Add half of the self raising flour and whisk in until you can't see any flour anymore
- Divide the mixture equally between three bowls, add red food colouring to one bowl, orange to another and yellow to the last one. Whisk until the desired colour is achieved
- Divide the mixture between the tins and bake for 20 minutes or until a skewer inserted in the middle comes out clean. Remove from the tins and leave them to fully cool on cooling racks
- Wash the tins, re-line and grease them, then repeat steps 3 - 7 but add the green, blue and purple food colouring instead
- To make the vanilla buttercream mix the butter and icing sugar together. Once it starts to come together add the vanilla extract and mix until smooth. I use my electric hand whisk to do this but you can also do it by hand with a spoon
- Start stacking the sponges on a plate or turn table. Spread a thin layer of buttercream onto each sponge, followed by a generous drizzle of lemon curd, before adding the next one
- Once the sponges are all stacked and filled with buttercream and lemon curd, cover the whole cake in a thin crumb coat of buttercream. Put it in the fridge for an hour to firm up
- Remove from the fridge and spread on a final and thicker layer of buttercream and smooth it out
- Put the remaining buttercream into a piping bag fitted with a nozzle of your choice and pipe some small rosettes around the edge of the cake
- Fill the middle of the top of the cake with rainbow sprinkles, and use a brush or your hands to add more sprinkles to the bottom edge of the cake
- Leftovers will keep in an airtight container for 3 days
Notes
If you like this, check out more of my Cake recipes!
Pin for later!
Cat | Curly's Cooking
This looks fantastic, one of the best rainbow cakes I have seen. I love their tall layers and bright colours and your decorations finish it off perfectly. The addition of the lemon sounds delicious, hope you had a lovely birthday.
thebakingexplorer
Thank you so much Cat!
Jodie
This looks amazing! I am going to try it tomorrow!
What Nozzle did you use for the piping of the buttercream on top?
thebakingexplorer
Thank you! It was a Wilton 8B nozzle. Let me know how it goes!
Kat
I’m making this on Monday for my daughters 5th birthday. I’m considering making the icing lemon flavour as well by using lemon extract in place of vanilla. Would you keep the measurements the same or would it end up too lemony?
thebakingexplorer
Hi Kat, I would keep the measurements the same. Once it's all mixed, taste the buttercream, as you may want to add more depending on how lemony you like it.
Hannah
Hi Kat,
Love this recipe - looks amazing. What tins would you recommend using for the sponge?
Thanks
thebakingexplorer
Hi Hannah, the tins I used are linked in the Amazon bar above the recipe 🙂 I use them for all my 8" cakes.
Midge @ Peachicks' Bakery
SO SO pretty! And happy birthday! The Peachicks have now demanded a safe version for their birthdays 'from now until forever'! Thanks for sharing with #CookBlogShare
thebakingexplorer
Haha uh oh! Thanks Midge 😀
Irene
So beautiful, happy birthday!
thebakingexplorer
Thank you Irene!
Kat @ Kat's 9 Lives
So pretty! I always think about making a rainbow cake...and then I get intimidated by all the layers! Yours looks great! Enjoy the weekend 🙂
thebakingexplorer
I've been the same for ages, but I really wanted one for my birthday and it wasn't actually that bad in the end! Having three tins definitely helps.
Arlene
What a beautiful cake! I hope you had a wonderful birthday! 🙂
thebakingexplorer
Thank you Arlene!
Of Goats and Greens
Very attractive! Thanks for sharing with Fiesta Friday.
thebakingexplorer
Thank you!
Corina Blum
I've never made a rainbow cake but this sounds delicious! I think it's a great idea to add the lemon curd and make it a lemon cake. Thanks for sharing with #CookOnceEatTwice!
thebakingexplorer
Thanks Corina! The lemon was the perfect flavour 🙂
Jhuls @ The Not So Creative Cook
Belated happy birthday, Kat! I am sure you did enjoy this beautiful and delicious cake! Thanks for sharing at Fiesta Friday party! Have a lovely weekend! x
thebakingexplorer
Thank you Jhuls!
Rebecca - Glutarama
This is so beautiful, your cakes never cease to amaze me. I have a set of rainbow cake pans, got them for my birthday last year o really ought to think about christening them, you've inspired me.
thebakingexplorer
Awh thank you Rebecca! I'm so glad it's inspired you!
Amy
I love lemon and this cake turned out so pretty. You may have given me the push that I needed to make the rainbow cake that I have been thinking about making!
thebakingexplorer
Yay I'm so glad I've inspired you!!
Amanda W.
Happy Belated Birthday Kat! did you have to trim any of the sides/top of this cake? thanks
thebakingexplorer
Thank you! I didn't trim the sides at all, I trimmed the top of a couple of layers if they 'domed' too much in the oven
Amanda
Oh my god Kat this is so freaking cute! Love love love the extra sprinkles around the bottom! Happy Birthday! xx
thebakingexplorer
Thank you so much Amanda!
Liz
Wow! This is a stunner!!! So pretty and beautifully iced!
thebakingexplorer
Thank you Liz!
Bethan
This is a brilliant recipe! And can I just say, the foil tin hack was just brilliant! My cake obviously looks nothing like yours since I'm not a baker but it turned out so much better than I expected! I am so disappointed I forgot the lemon curd though as the cake was quite sweet with just the lemon zest (probably because I used the icing like cement too) lots of fun to make for an amateur like me though! Thanks for this! X
thebakingexplorer
Thank you so much Bethan! I'm so pleased to hear you liked the recipe 😀
Leanne Bugeja
Hi,totally love this recipe. In the buttercream can I use lemon extract instead of vanilla?
thebakingexplorer
Thank you! Yes absolutely!
Betsy Drewes
This looks amazing! I don't have a kitchen scale. Do you have the recipe using cups and tablespoons?
thebakingexplorer
Thank you! You could convert it by checking my conversion guide here: https://thebakingexplorer.com/ingredients-conversions/ however, I do recommend using scales as it's so much more accurate, and they're so cheap to purchase!
Kasia
Your cake looks amacing Kat!
I’d like to make it for my son but he doesn’t like lemon curd ... could I use a different sauce? What would you recommend please?
thebakingexplorer
Hi Kasia, thank you! You could use his favourite jam instead, or just leave out the lemon curd if you prefer!
jill
lovely looking cake, but the recipe is a bit all over the place, it's says 4 lemon zest in the sponges section, but it doesn't say to add it into the mixture? Don't know why 10 eggs have been used either? Seems a lot? The vanilla extract is also in the buttercream filling ingredients, but the recipe suggests putting it in the sponge mix??
thebakingexplorer
Hi Jill, you are right I had to add vanilla extract in the sponge when it should be lemon zest - I've fixed that one error now. I used 10 eggs for the recipe so that's why it says 10 eggs. It sounds like you haven't made the cake so I'm wondering why you've rated it 3 stars if you haven't made it?
Leanne
Hi, have you ever made it and froze the sponges for a few days, just wondering if I could make it a few days before? Also I saw someone mention the tin foil trick- what is this? Making this for my daughters first birthday so want it to be the best it can be! Thanks x
thebakingexplorer
Hi Leanne, yes you can definitely freeze the sponges. Wrap them well individually in cling film. Don't pile them all on top of each though as the weight will flatten the ones on the bottom! I hope you enjoy the cake 🙂
Kat
I made two layers of this cake as an experiment (I haven’t made a cake in about 15 years so wanted to practice before going for all six!) and it turned out absolutely gorgeous. Light and fluffy and full of flavour. My friends raved about it. Thanks for this excellent recipe, I can’t wait to try the full rainbow!
sheena
Amazing recipe! Baked this on the weekend and it came out perfect! Took a bit of time but definitely worth it. Added skittles on top for the extra rainbow look lol. Thanks!
thebakingexplorer
Thank you Sheena!! Love the skittles decoration - great idea!
Ash
First attempt at this last weekend and it turned out great! Amazing recipe, so delicious and pretty! Doing it again this weekend (practicing for my nephews birthday!) and was just wondering if you used any dowels? Or if you had any other suggestions as I might have had a few sliding layers last weekend... haha! Thanks Kat!
thebakingexplorer
Hi Ash, I'm so glad you liked the recipe! I haven't had to use dowels, but if you are having trouble I would recommend using three spaced evenly around the cake. I hope that helps!
Rosie
I have made this cake for four different birthdays and it's so easy to make and looks really impressive! For two birthdays I halved the recipe and did just a three layered cake to save time but it still looks great.