Lemon Rainbow Cake

Lemon Rainbow Cake

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!

Step by step…

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!

Lemon Rainbow Cake

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!

Lemon Rainbow Cake

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.

Recommended equipment & ingredients*

8″ cake tins Mixing bowls Cooling rack
Kitchen scales Round cake tin liners Electric hand mixer
Decorating turntable Angled palette knife Buttercream scraper/smoother
Piping bags Wilton 8B Piping nozzle Red food colouring
Yellow food colouring Orange food colouring Green food colouring
Purple food colouring Blue food colouring

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More rainbow recipes…

Rainbow Cupcakes
Rainbow Cupcakes

More lemon recipes…

Lemon Meringue Cupcakes Triple Lemon Cake
Lemon Meringue Cupcakes Triple Lemon Cake Lemon Cupcakes with Lemon Curd Filling
Lemon Curd Cheesecake Lemon Curd & White Chocolate Bread Rolls
Lemon Curd Cheesecake Lemon Curd & White Chocolate Bread Rolls Lemon Meringue Dessert Pots
Lemon Rainbow Cake
4.82 from 11 votes
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Lemon Rainbow Cake

Multi coloured rainbow cake with lemon curd filling

Course Dessert
Cuisine American
Keyword Cake
Prep Time 40 minutes
Cook Time 20 minutes
Total Time 1 hour
Servings 16
Author thebakingexplorer

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

  1. 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!

  2. Pre-heat your oven to 160C Fan/180C/350F/Gas Mark 4, and grease and line your 8" cake tins

  3. 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

  4. Add half of the eggs, milk and lemon zest, and whisk until fully incorporated

  5. Add half of the self raising flour and whisk in until you can't see any flour anymore

  6. 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

  7. 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

  8. Wash the tins, re-line and grease them, then repeat steps 3 - 7 but add the green, blue and purple food colouring instead

  9. 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

  10. 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

  11. 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

  12. Remove from the fridge and spread on a final and thicker layer of buttercream and smooth it out

  13. 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

  14. 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

  15. Leftovers will keep in an airtight container for 3 days

If you like this, check out more of my Cake recipes!

Lemon Rainbow Cake

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43 comments / Add your comment below

  1. 5 stars
    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.

      1. This looks amazing! I am going to try it tomorrow!
        What Nozzle did you use for the piping of the buttercream on top?

  2. Hi Kat,
    Love this recipe – looks amazing. What tins would you recommend using for the sponge?
    Thanks

    1. Hi Hannah, the tins I used are linked in the Amazon bar above the recipe 🙂 I use them for all my 8″ cakes.

    1. 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.

  3. 5 stars
    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!

  4. 5 stars
    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.

  5. 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!

    1. 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

  6. 5 stars
    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

  7. Hi,totally love this recipe. In the buttercream can I use lemon extract instead of vanilla?

  8. This looks amazing! I don’t have a kitchen scale. Do you have the recipe using cups and tablespoons?

  9. 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?

    1. Hi Kasia, thank you! You could use his favourite jam instead, or just leave out the lemon curd if you prefer!

  10. 3 stars
    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??

    1. 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?

  11. 5 stars
    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!

  12. 5 stars
    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!

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