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Easy Rhubarb and Custard Cake

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Want to know how to make a rhubarb and custard cake? So did I. That’s why I fashioned together this helpful post just for you! I’ve always absolutely loved the whole rhubarb and custard combo.

If you do too you should totally check out my rhubarb and custard ice cream recipe too! So I figured, why not turn it into a cake? In this post you’ll learn how to make your very own rhubarb and custard cake using my simple step by step pictures and top tips to help you every step of the way.

Slice of rhubarb and custard cake on a plate with a fork

I’ve come to realise that rhubarb and custard is a bit of a Marmite flavour combo. Me? I think it’s incredible! Others, not so much. I will say this though – turning such a classic combination into a cake was really fun for me! It presented a challenge working out the best way to incorporate both flavours so you could really taste them but I think I’ve cracked it.

With a custard flavour sponge and icing sandwiched together beautifully with a delightful rhubarb jam, you can’t really ask for much more in life can you?! The flavours work so well together it’s like Bonnie and Clyde or Romeo and Juliette – they were just meant to be together!

Rhubarb and custard cake on a cake stand

If you use this rhubarb and custard cake recipe, I guarantee you will be back to make seconds. It’s CRAZY delicious and too moreish for it’s own good!

I say this a lot but don’t forget to read through the whole recipe before starting. There’s nothing worse than getting to a critical stage and realising you’ve forgotten something! It could end up being less of a rhubarb and custard cake and more of a rhubarb and custard mess.

In fact, this is one of my Top 5 Tips to Guarantee Baking Success! You can bag a deeper explanation, plus the other 4 tips in this baking for beginners guide.

Love custard but not a huge rhubarb fan? Use a different flavour jam or try my custard cream baked cheesecake instead – it’s heavenly! You can always go for the all time classic victoria sandwich cake too, you can never go wrong with that one!

Slice of rhubarb and custard cake on a plate with a fork

Rhubarb and Custard Cake Recipe Tips

  • Make sure all your fridge ingredients are at room temperature before you start. Not only will it make life easier for you but batters work much better when everything is the same temperature.
  • Don’t open the oven until the last 5 minutes of baking. And only do this to check if it’s done or not – otherwise your cake may collapse.
  • Allow the sponge to cool completely before attempting to decorate or your filling will melt everywhere! Not ideal.
  • Bake cakes in the lower part of your oven to help prevent domes from forming in the middle.
  • If you can, make your own rhubarb jam instead of buying one. It will take your cake to a whole new level! (See later on for a link to a great recipe.)
  • Never store cake in the fridge. Fridges draw moisture from food so it will dry out your cake! Nobody wants dry cake.
  • Be careful when adding liquid to the icing. That custard powder wants to become a liquid – this is not what you want in your icing!
Rhubarb and custard cake on a cake stand

Easy Rhubarb and Custard Cake – Step by Step Picture Recipe

Here is what you will need to serve 10-12.

Ingredients

For the Cake

  • 200g Golden Caster Sugar
  • 200g Unsalted Butter, Room Temp
  • 4 Eggs, Room Temp
  • 200g Self Raising Flour
  • 80g Custard Powder
  • 1 tsp Baking Powder
  • 3 tbsp Milk, Room Temp
  • 1/4 tsp Salt

For the Filling

  • 160g Icing Sugar
  • 50g Custard Powder
  • 100g Unsalted Butter, Room Temp
  • 1 tbsp Milk
  • 300g Rhubarb Jam or Compote
  • Icing Sugar, For Dusting (Optional)

Essential equipment

  • 2 x 20cm (8″) Round Sandwich Cake Tins
  • Electric Stand Mixer or Electric Hand Whisk

Cake instructions

Lightly grease and line your baking tins then preheat your oven to 180°C/Fan 170°C.

Add all the cake ingredients into the bowl of an electric stand mixer (or a large bowl with an electric hand whisk).

Unmixed rhubarb and custard cake batter in a stand mixer bowl

Then give it a good mix until all the ingredients are blended well, smooth and you can’t see any more flour. Don’t overdo it though! Mix only until everything is blended and smooth.

Rhubarb and custard cake batter in a stand mixer bowl

Evenly divide the batter between the two prepared tins and smooth out.

Rhubarb and custard cake batter in two lined sandwich tins

Place both onto the lower shelf in the oven and bake for 12-18 minutes until a skewer inserted into the middle comes out clean.

Baked rhubarb and custard cake in two sandwich tins

When you can handle the tins – remove the cakes, peel off the baking paper from the bottoms and place them onto a wire rack to cool completely before decorating.

Filling instructions

Sift the icing sugar and custard powder into the bowl of an electric stand mixer (or a large bowl and use an electric hand whisk) then weigh in the butter. Having the butter at room temperature here will make your life MUCH easier!

Rhubarb and custard cake icing ingredients in a stand mixer bowl

Beat on slow to begin with then, once the powdered ingredients have blended in, crank up the speed and give it a really good beat for at least 3 minutes. When it’s nice and smooth, add in 1 tbsp of milk. Be really careful not to overdo this – due to the added custard powder this frosting is liable to become more liquidy much easier than a regular frosting. Then give it a final beat for another minute or 2 until light and smooth.

Rhubarb and custard cake icing in a stand mixer bowl

Assembly and decoration instructions

Time to decorate your rhubarb and custard cake! First thing’s first, make sure those sponge layers are completely cool before you begin. They are? Well then we need to make sure they’re level. Mine weren’t quite so I simply lay them flat and carefully sliced off any ‘dome’ using a sharp knife. (I have hot spots in my oven so one side always seems to get bigger than the other!)

Two sponge cakes on a cooling rack with the domed parts leveled off

Take one sponge layer and place it on a cake stand or serving plate. Now you can do one of two things here. Ignore the whole making it look ‘pretty’ thing and just whack on all the icing then smooth it out with a spatula.

Or, you can load the icing into a piping bag fitted with a large round nozzle (or just snip a larger piece than usual off the end) and pipe blobs around the edge of the sponge.

Fill in the rest of the middle with a big spiral. It doesn’t matter about piping blobs in the middle as no one is going to see that part – even when you cut into it!

Sponge cake with custard icing piped on top in blobs

Next, pop that rhubarb jam into a little bowl and give it a little mix to loosen it up a little. If you like you can add a little pink (or red) food colouring gel here to liven up the colour.

Rhubarb jam in a small bowl with a spoon

Now pour it out into the middle of the custard frosting and gently spread it over the top taking it almost to the edges. (Remember that these filling ingredients will get a bit squashed when you put the top layer on!)

Sponge cake with custard icing piped on top in blobs topped with rhubarb jam

I didn’t heed my own advice and this is what happened…

Rhubarb and custard cake on a cake stand

It’s not really that pretty is it?! At least now you know I’m actually human haha.

So carefully place the final cake layer bottom side up onto the top of the cake. (This will give you a nice flat top.)

Rhubarb and custard cake on a cake stand

And that’s it! All that’s left to do is generously dust the top with icing sugar just before serving. Store your cake in an airtight container (preferably metal) at room temperature and consume within 3-4 days.

Slice of rhubarb and custard cake on a plate with a fork

My biggest tip for this recipe would be to go the extra mile and make your own rhubarb jam. There’s nothing quite like it and it adds so much to this recipe. Shop bought ones are ok but I’ve found them to be much sweeter and they actually seem to mask the earthy rhubarb flavour that we all know and love.

This easiest rhubarb jam recipe from Christina is really simple to make and absolutely beautiful!

Loved this rhubarb and custard cake recipe? Pin It!

Slice of rhubarb and custard cake on a plate with a fork
Slice of rhubarb and custard cake on a plate with a fork
Slice of rhubarb and custard cake on a plate with a fork

Rhubarb and Custard Cake - Printable Recipe

Yield: 12 Servings
Prep Time: 35 minutes
Cook Time: 15 minutes
Total Time: 50 minutes

This rhubarb and custard cake will become a household favourite! It's really simple to make and tastes absolutely divine.

Ingredients

For the Cake

  • 200 g Golden Caster Sugar
  • 200 g Unsalted Butter, (Room Temp)
  • 4 Eggs, (Room Temp)
  • 200 g Self Raising Flour
  • 80 g Custard Powder
  • 1 tsp Baking Powder
  • 3 tbsp Milk, (Room Temp)
  • 1/4 tsp Salt

For the Filling

  • 160 g Icing Sugar
  • 50 g Custard Powder
  • 100 g Unsalted Butter, (Room Temp)
  • 1 tbsp Milk
  • 300 g Rhubarb Jam or Compote
  • Icing Sugar, (For Dusting - Optional)

Essential Equipment

  • 2 20cm (8″) Round Sandwich Cake Tins
  • 1 Electric Stand Mixer or Electric Hand Whisk

Instructions

To Make the Cake

  1. Preheat your oven to 180°C/Fan 170°C and grease/line the base of your baking tins.
  2. Put all the cake ingredients in an electric stand mixer and beat until smooth.
  3. Divide between the two tins and bake in the lower part of your oven for 12-18 mins until a skewer or knife poked in the middle comes out clean.
  4. Remove from the tins, peel off the baking paper and cool completely on a wire rack.

To Make the Custard Buttercream

  1. Put the icing sugar, custard powder and butter in an electric stand mixer and beat until light and smooth. If it's still too thick, add 1 tbsp of milk and beat again until smooth.

To Decorate

  1. If your cakes have domed - level them out with a sharp knife.
  2. Either spread the custard buttercream straight over the top of one of the cake layers with a spatula or load a piping bag with a large round nozzle/snip a chunky piece off the corner. Then pipe blobs around the edge and swirl the rest in the middle.
  3. Put the rhubarb jam in a bowl and mix until loosened. (You can add a little pink food colouring here if you want to.)
  4. Spread the jam carefully over the top of the buttercream, almost right to the edge but not quite.
  5. Add the other cake layer bottom side up onto the top. Sieve icing sugar generously over the top and serve.

Notes

Store in an airtight container at room temperature and consume within 3-4 days.

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Nutrition Information:
Yield: 12 Serving Size: 1
Amount Per Serving: Calories: 538Total Fat: 24gSaturated Fat: 14gTrans Fat: 0gUnsaturated Fat: 9gCholesterol: 126mgSodium: 374mgCarbohydrates: 77gFiber: 1gSugar: 55gProtein: 5g

Nutritional information on kitchenmason.com should only be used as a general guideline, I am not a certified nutritionist. Please always check labels for allergens where applicable.

Did you make this recipe?

I'd love to hear about it! Please leave a comment on the blog or tag me on Instagram.

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Alison

Friday 16th of September 2022

I'm.womdering how this could.make individual.cupcakes for a macmillan cancer fundraiser. Do you have any suggestions? I'm a new Baker.

Emma

Friday 16th of September 2022

Hi Alison. I would make the cake batter as per the recipe. Fill a cupcake tin with foil cases and half fill each of those with batter. Bake for around 12-14 minutes until a skewer inserted comes out clean. Then allow to completely cool before topping with a little jam and frosting. Hope this helps! Emma x

Christina | Christina's Cucina

Monday 30th of July 2018

O.M.G. I drooled from beginning to end on this post! I cannot wait to try this myself as I have plenty of rhubarb jam! I love that you showed the jam spilling over, too! Yes, it happens to all of us! :) Thanks for sharing, I love it!

Miss KitchenMason

Monday 30th of July 2018

Haha yes, nobody is perfect - there's a lot of mishaps behind the camera! Thank you so much for your kind words Christina. Emma x

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