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This gorgeous Rose Rhubarb Layer Cake is what you need to celebrate a special occasion! Vanilla sponge layer cake filled with rhubarb curd and covered with mascarpone frosting.
For a simple everyday cake, take a look at my Rhubarb Cake Sharlotka. 
I don’t bake grand layer cakes often but when I do my heart and soul go into them. I imagine myself in a top bakery where everything is possible. Where I can have my dream cake. Then I build my cake…in my mind.
You would think that after that process I’d be set but you would be wrong. Even on the baking day I change my mind again and then again and then again…I change it at least 500 times.
In this instance I changed what type of sponge I wanted, what type of icing I wanted and decorations but one thing remained constant. Rhubarb Curd. I knew from the start the cake would revolve around it. I knew I wanted to make a rhubarb layer cake.
Let me tell you no one was disappointed, most importantly I wasn’t disappointed. The cake we had for Easter was lighter than a cloud, vanilla bean flavoured sponge, layered with sweet and slightly tart rhubarb curd and encased in luscious rose water mascarpone cream.
As much as I love a good chocolate cake delicate vanilla and fruit cakes have a special place in my heart. This one is so light and springy!!
Don’t be intimidated by the lengthy recipe card and time spent in the kitchen. I tried to be as detailed as possible, which made it long! Also, this cake is WORTH IT!
Recipe Tips and Notes
- Prepare the rhubarb curd at least one day before baking the cake. It needs time to chill and set in a fridge. The curd is thickened with cornstarch. A firmer than usual consistency is necessary for the curd to stand up to the cake layers.
- Follow instructions for the cake sponge carefully. This particular sponge recipe is very delicate and very light, similar to Angel’s Food cake but it uses whole eggs instead of just egg whites. The height of the sponge is 100% reliant on the eggs and how well they are whipped. For detailed instructions, read this article and watch the video.
- Soak the sponge layers with the syrup to add more moisture and flavour during the assembling of the cake.
- Finally, mascarpone tends to separate if over-whipped. Both mascarpone and the heavy cream need to be straight out of a fridge. Use the instructions as written if using double cream. If using whipping cream, whip the cream first until soft peaks form, then fold it into slightly whipped mascarpone. This extra step prevents the icing from separating and especially relevant to the US and Canadian readers due to the dairy products variation.
If you make this Rhubarb Layer Cake, I would love to see your photos! Tag @vikalinka when you share them on Instagram!
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More layer cake recipes
Rose Rhubarb Layer Cake
Ingredients
For the Rhubarb Curd
- 400g(4 long stalks) rhubarb
- 3 eggs, large
- 170g/3/4 cup unsalted butter, cubed
- 3 tsp cornflour/corn starch
- 150g/3/4 cup caster sugar/ granulated sugar
- a drop of pink colouring, optional
For the Cake
- 5 eggs, room temperature, large
- 200g/1 cup white granulated sugar
- 1 vanilla bean, seeds scraped out
- 140g/1 cup all purpose/plain flour
For the Syrup (for soaking the sponge layers)
- 4 tbsp elderflower liqueur
- 4 tbsp simple syrup, a solution of water and sugar in equal parts
- 2 drops rose water
For the Mascarpone Cream
- 500g/2 cups mascarpone, chilled from fridge
- 250ml/1 cup double/whipping cream
- 100g/1/2 cup icing sugar
- 2 tsp This is an affiliate link.vanilla
- 2-3 drops rose water , or less depending on the strength of rose water
For decoration
- lemon thyme sprigs
- organic pink flowers
- dried rose petals
Instructions
For the Rhubarb Curd
- *Prepare the rhubarb curd at least a day before assembling the cake. Wash and cut rhubarb stalks in 2″ sections, put them in the bowl of a food processor and process until then turn into a pulp. Push it through a fine sieve with a spoon to extract all the juice, then discard the pulp. You should get about 300 ml/ 1¼ cup of rhubarb juice.
- In a food processor or blender mix eggs, sugar and cornflour/corn starch until you have a homogenous mixture with no lumps remaining. Alternatively you can do this step by hand using a bowl and a whisk.
- In a saucepan combine 1 cup of rhubarb juice, egg, sugar and corn starch mixture and cubed butter, set the pan over low heat and star cooking it while stirring with a whisk the entire time until butter melts and the curd thickens. Do not turn the heat up to speed up the process or the eggs will turn into scrambled eggs and the curd go lumpy!
- Take off the heat when the curd is the consistency of thick sour cream. You may push it through a fine sieve again to ensure there are no lumps and the curd is silky smooth. Add the remaining rhubarb juice to increase the tart flavour of the rhubarb and a drop of pink food colouring if desired as the curd loses its colour when cooks!
- Chill in the fridge for at least 3 hours or overnight. The rhubarb curd will thicken when chilled.
For the Cake
- Preheat the oven to 350F/180C.
- Grease 3 8″ cake pans and line them with parchment paper. (Don’t be tempted to skip this stage, the sponge is very delicate, so it’s important to use parchment paper for easy removal.)
- Crack 5 eggs at room temperature to a bowl of a stand mixer and add sugar and vanilla been seeds, beat at high speed for 5 minutes until the mixture is pale and triples in volume.
- Fold in flour through a sifter in 3 additions blending it in gently after each addition. Your goal is to keep the volume of the egg mixture so be very careful in this step of the process.
- Divide your cake batter among 3 pans, I weigh mine to make sure they are exactly the same and bake for 25-30 minutes until cake tester or tooth pick comes out clean and the cakes have risen to the top of the pan. (I baked 2 layers and then 1 later).
- Cool for 10 minutes and then run a knife around the edges of your pans to release the cakes and flip them over on a wire rack to cool completely.
- (After your cakes have cooled you can individually wrap them in plastic wrap for later use. You can bake you sponge layers up to 2 days ahead.)
For the Syrup
- In a measuring cup mix together simple syrup, elderflower liqueur for beautiful floral notes and 2-3 drops of rose water, the amount of which largely depends on the strength of it. Each brand is different, so it's important to taste and smell to determine the desired amount. Add with caution as it can smell like a perfume instead of a dessert if too much rose water is used.
For the Mascarpone Cream
- In a bowl of a stand mixer whip well-chilled mascarpone for no longer than 30 seconds with a balloon attachment until light, add heavy/double cream, icing sugar, vanilla and rose water and whip for 1-2 minutes longer until it looks like thick whipped cream. If your mascarpone cream is too thick and hard to spread add a splash of heavy/double cream and whip for just a few seconds longer to loosen it.
Assemble the cake
- Load 1/3 of mascarpone cream in a large piping bag with a plain round tip.
- Pipe a border around the first drizzled with syrup layer, this will prevent rhubarb curd filling from spilling out, fill the space inside the border with rhubarb curd.
- Top with the next layer and repeat the actions. Place the third layer on top and cover the entire cake with a thin layer of mascarpone cream also known as crumb coating. Place in the refrigerator for 30 minutes. When the crumb coat is firm frost the cake with the rest of the mascarpone cream.
- Decorate the top with lemon thyme, small organic pink flowers and rose petals.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
I made this last year as one of my wedding cakes (The other was a chocolate cake with passion fruit curd and a white chocolate cream cheese frosting, the two cakes were a great contrast!) and it got wonderful reviews from the guests! I did purchase elderflower syrup instead of making my own because, well, weddings are stressful. If you’re at all interested, I made all of the cakes about a week in advance and kept them in the freezer. I made the curd a few days before the wedding – canning and preserving it. The morning of the wedding I defrosted the cakes by just letting them sit in the fridge, made the frosting, and assembled the cake. Be mindful when making the frosting to not over mix! I almost did! I didn’t have any issues of the cake melting, though it didn’t sit out for long before cutting. Our wedding was late June in New York.
Very impressive, Morgan! Thank you for sharing with us!
Overall, mixed success with this recipe. The taste of the rhubarb curd was AWESOME, but it seems to have too much butter. It separated during cooking (and it was stirred with a whisk continuously). I wonder if the description “consistency of thick sour cream” led to overcooking; I am used to making cured with the “coats the back of a spoon” guideline. I passed that stage during the cooking and then it separated. Once chilled, it needed to be remixed in food processor. But very interesting and very good. I think it would be great on toast.
Second issue was with cake. I don’t have a stand mixer, so used a hand held mixer. It whipped the eggs well, but perhaps would have had a better result if eggs were whipped separately before adding sugar. the cake was light; Very thin layers. Not much flavor in it.
Recipe mentions syrup but directions do not specify when to soak layers in syrup, so I did it as I assembled the cake. Should they have soaked more?
Finally, the icing was disappointing. Whipping cream separately and then combining would have made it lighter. There was too much for the amount of cake; not enough sugar to my taste. There are better mascarpone icing recipes.
The cake was beautiful and the combination of rose and rhubarb was really exciting, so this is worth trying. Overall I was happy to do it, but is does not rank among my greatest successes.
Hello
Can you please confirm the quantity of ingredients are correct for the sponge? . Seems low flour and sugar quantities for triple layer 8” cake only one cup of each.:
Eggs room temperature- 5 large
Sugar- 1 cup
Vanilla bean seeds scraped out
Flour- 1 cup
Hope to hear from you soon as I am keen to make this
Kind regards
Pauline
Hi Pauline, the measurements are indeed correct. It’s a family recipe that I’ve made more times than I can count. The instructions need to be followed carefully for the success of the recipe.
Many thanks for your prompt reply. I’m guessing the extra eggs and the beating somehow increase the volume?
Yep, that’s exactly it.
I just made this recipe for a birthday party and it was a HUGE hit! Everyone loved it! A perfect summer cake. Great recipe!! Thanks so much for sharing!
I am so happy to hear it, Charlie! That cake is beautiful in the summer. I love rhubarb!
Thank you for sharing!
I made the curd last night and am planning to make the rest tonight, however the curd has a slightly lumpy texture and leaves a fat coating in the mouth. It has a slightly cloudy taste. I haven’t put it through a sieve yet as the lumps appear smaller than what would go through a sieve.
Should I start again or can I rescue my curd somehow ?!
Hi Louise, lumps usually happen from a lack of stirring with a whisk or the curd being on high heat, which makes it thicken too fast and go lumpy. I would try putting it in a blender or a food processor for a smoother texture. There shouldn’t be any fat coating either. It has the same texture as lemon curd.
i have my rhubarb curd chilling in the fridge. I just went to check on it and it’s separating. I looks like clarified butter is settling on the top. What should I do?
Hi Leanna, did you let it cool sufficiently before you put it in the fridge? You can try to save it by bringing it to a room temperature and then beating it with a whisk until it’s well blended.
Would it be possible to bake this cake in 6″ cake pans?
Hi Leanna, I haven’t tried it but you can always experiment a bit, and hopefully your cakes will be a bit taller and just as fluffy and delicate!
Hi.. I was awed by its simplicity and yet, hues popped out of life. .. I have been searching for organic edible flowers. Where do you buy them? Do you have a list of edible flowers? Thank you for sharing and your time.
Hi Beth, I usually grow my own organic flowers for decoration but farmer’s markets are your best bet for finding some. I also used dried rose petals and you can find them in Middle Eastern Shops or Amazon. Unfortunately I don’t have a comprehensive list of all edible flowers but I am sure there are many online.
Hello! I want to attempt to make this but put it in the form of mini cupcakes for a baby shower! I just had a question about the Elderflower. If I leave it out, due to the guest of honor being pregnant, will it make a dramatic difference in the flavor? Is there anything I could substitute in it’s place?
Hi Kacey, you can substitute an elderflower liqueur with an elderflower cordial, which is alcohol free. Elderflower has a beautiful flavour, which is hard to match but if you can’t find it, you can add a bit of vanilla to your syrup.
okay perfect! thank you so much!
You are welcome! Enjoy!!