The Perfect Rainbow Layer Cake

The Perfect Rainbow Layer Cake

If you follow me on instagram you might have seen this pretty good attempt at a rainbow cake that I made earlier this week with my boyfriend. ‘Normal’ couples go on romantic walks or go out for dinner on Valentine’s Day, we, however, baked a rainbow cake.


We followed the Cupcake Jemma (sorry not sorry) recipe I’ve linked below for the pretty much everything with the only real difference being that we made the outside of ours pink and threw on as many different types of sprinkles as we could.


Most of the time if I can save myself buying specific equipment I will but in all honesty, most of the things she recommends using in this are essential, although there are alternatives for some things. The biggest advice I can give you if you’re attempting to make this is to use colouring paste instead of normal food colouring. Yes, it’s annoying having to order it on amazon (I’m yet to see it anywhere else) but the difference is huge. It’s so obvious to me from this one recipe why professionals use paste instead of liquid or gel. If you want strong, vibrant colours you have to use paste. I’ve linked the one I used down below.


Rainbow Layer Cake - Lucy Tregidon


Similarly, it might be a tiny and seemingly insignificant piece of equipment but having a cake scraper around really does make your life a lot easier. I’ve never actually made anything bigger than a lemon drizzle cake before attempting this and I definitely hadn’t attempted icing anything other than cupcakes. I knew that without a scraper this cake would just look like a huge mess and I think I was right. I didn’t use it for the crumb coat because I sort of forgot about it and lets just say I got so frustrated with it I had to leave it overnight and finish icing it the next day. There is no way those sides would look anything close to neat or straight without it.


In her video Jemma recommends buying a turntable to put the cake on whilst you ice it. When rummaging around the cupboards at home looking for substitutes so I didn’t end up buying things I could’ve done without I came across the lazy Susan that’s been sitting in a cupboard forgotten about for a while. They work exactlythe same. Having something to put the cake on that rotates was definitely helpful, but if you’ve got something you can use in place of buying a turntable, give it a shot!



Similarly, when leveling the individual layers Jemma uses a cake leveler to create nice even surfaces. Whilst its not an equivalent by any means, I just used a serrated knife and it did the job okay. It probably does take longer than using a cake leveler but for the hobby baker I am it worked fine.


This is probably my favourite thing I’ve baked so far and I’m super proud of how it turned out. As mentioned, it was looking a little touch and go after the crumb coat but as Dr Seuss once said, “everything stinks til its finished”. I also learnt a very good life lesson in that if ever baking isn’t looking good, there’s very little that pink vanilla buttercream and sprinkles can’t fix.


What do you think of my rainbow cake? Do you think you’ll be attempting one any time soon? Leave your answers and any more questions you have in the comments below!

Lucy x



Suggested equipment:

(This is the exact colouring paste I used, I’d definitely recommend it and the colours in the photos speak for themselves!)



Jemma’s Recipe:
For the cake:
9 tbsp whole milk
1 ½ tsp vanilla extract
Various colour pastes (red, orange, yellow, green, blue & purple)
750g soft unsalted butter
750g caster sugar
9 large free-range eggs
750g sifted self-raising flour
Butter & flour for preparing the cake tins

For the buttercream:
400g soft unsalted butter
900g sifted icing sugar
5-6 tbs whole milk
½ tsp vanilla extract


There isn’t a person on earth who isn’t a fan of rainbows, right? Right?? Well, if there is then they must be very sad and lonely. But you and I know that rainbows are magical and brilliant and what better way to give the rainbow the respect it deserves than to embody it in cake form. This one's quite a lengthy watch, so put the kettle on, put your feet up and prepare for some top tips for baking and decorating the perfect Rainbow Cake. This video is going to knock your socks off!