Rhubarb Custard Cake
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At the first sighting of rhubarb last week at the market, I loaded up my cart with two visions in mind: 1. Rhubarb Schnapps, a spring tradition. 2. Bon Appetit’s Rhubarb Custard Cake, one of the most delicious things I made last summer.
I discovered the recipe last July, late-ish as far as rhubarb season goes, and managed to make it a few times before summer ended and my attention turned to Brussels sprouts, sweet potatoes, and all the winter squashes. But I dreamed about this cake all winter, contemplating many a variation with apple or pear or quince, none of which materialized.
When I made this cake last week for the first time in months, I was reminded why I love it so much: its custardy texture, its sugary crust, its perfect sweet-tart flavor profile. Plus: rhubarb. Is there anything better?
This cake comes together relatively quickly, too, requiring three basic steps: 1. Mixing the dry ingredients. 2. Beating eggs with sugar. 3. Whisking wet ingredients. After you combine these three elements, you arrange rhubarb slices on top and pop it to the oven. Forty-five minutes later it’s done, emerging with sugary rhubarb slices bobbing in a custardy but cake-y base.
I find this cake tastes best the day it is made, though it makes a fine breakfast on day two. With that in mind, I wouldn’t hesitate to serve this as part of a festive spring brunch.
A Few Tips
If you’ve seen the BA photo of this cake, you may feel inspired to arrange your rhubarb slices artfully atop the cake batter, perhaps in a chevron or herringbone motif. I encourage you mostly not to bother — most of the slices will sink below the surface of the batter, rendering your efforts fruitless. But if you are eager to try, here are a few things I have found helpful for keeping those rhubarb slices afloat:
- Chill the batter longer than the recommended 10 minutes.
- Let the butter cool to room temperature — not so that it begins to firm up, but so that it is in fact cool to the touch.
- Cut wide slices of rhubarb lengthwise in half or into thirds before cutting them crosswise to ensure the pieces are as light as possible.
- Use all 13 oz. of rhubarb, laying the pieces of rhubarb that do not fit in a single layer on top of the first layer.
That’s it! I hope you make and love this one.
PS: Rhubarb-Frangipane Galette | Rhubarb Schnapps | Buttermilk Panna Cotta with Rhubarb Compote
Here’s the play-by-play: Steel yourself for a three-bowl job — don’t worry; it comes together quickly.
The batter needs to rest for at least 10 minutes in the fridge before receiving its rhubarb topping.
PrintRhubarb Custard Cake
- Total Time: 1 hour
- Yield: Serves 8
Description
Source: Bon Appetit
Notes:
- It is not recommended to mix the batter for this cake in a mixer, and there is no need — with about a minute of vigorous beating with a whisk, the eggs and sugar become lemony in color and thick and ribbony in texture.
- If you are avoiding alcohol, substitute a tablespoon of vanilla for the rum.
- Your rhubarb slices, no matter how lightly you place them atop the batter, will mostly sink. A few things I have found that help keep them afloat: 1. Chill the batter for longer than the recommended 10 minutes. 2. Let the butter cool to room temperature. 3. Use all 13 oz. of rhubarb, laying the pieces of rhubarb that do not fit in a single layer on top of the first layer.
- Original recipe calls for buttering and flouring the pan, but I like to use sugar — it creates an irresistible crust.
Ingredients
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4 tablespoons melted unsalted butter, cooled, plus more room-temperature for pan
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1 cup (128 g) all-purpose flour, plus more for pan
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¾ teaspoon baking powder
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½ teaspoon kosher salt
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2 large eggs
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1 large egg yolk
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1½ cups (328 g) sugar, plus more for sprinkling
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¼ cup sour cream
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2 tablespoons dark rum or Brandy, see notes
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zest from one lemon
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13 oz. rhubarb stalks, cut in half or thirds lengthwise if thick, then cut crosswise into 2-inch pieces
Instructions
- Preheat oven to 350°F. Butter and sugar (see notes above) a 9-inch springform pan — (to sugar: sprinkle about a tablespoon of sugar into the buttered pan, shake it all around to distribute the sugar evenly, tap out excess.)
- Whisk the baking powder, salt, and 1 cup all-purpose flour in a medium bowl. Whisk the eggs, egg yolk, and 1½ cups sugar in a large bowl until very pale and thick, about 1 minute. Whisk melted butter, sour cream, rum, and lemon zest in a small bowl. Whisk butter mixture into egg mixture just to combine. Add dry ingredients and fold in until batter is smooth; scrape into prepared pan. Chill 10 minutes (or longer) to let batter set.
- Arrange rhubarb over batter however you like, trimming as needed. Don’t press fruit into batter—just place over top and let it rest on the surface. Don’t fuss too much about how you arrange the rhubarb on top because most of it will sink into the batter. Sprinkle with more sugar — I use a tablespoon — and bake until cake is golden on top and browned around the sides, about 45 minutes. If you have an instant read thermometer, it should register at least 210ºF. This make take more or less time depending on your oven temperature and material of your pan.
- Transfer pan to a wire rack and let cake cool in pan 10 minutes. Slide a knife around sides of cake to loosen and unmold. Slide directly onto rack and let cool completely.
- Prep Time: 15 minutes
- Cook Time: 45 minutes
- Category: Dessert
- Method: Oven
- Cuisine: American
This post may contain affiliate links. Please read my disclosure policy.
90 Comments on “Rhubarb Custard Cake”
The rhubarb cake was such a treat, coming just in time for the rhubarbs arrival in the garden. House guests went crazy over it!! I might toss some orange zest next try but it was perfect just as it was!! Thank you!
Oh yay! So happy to hear this, Donna!
i wonder if i could swap greek yogurt for sour cream? since i always seem to have it in my fridge?
I imagine yogurt would work well here!
oh good i will try and report back!
Do you think reducing the quantity of sugar would ruin the result?
Looks outstanding!!!
It’s so yummy Olivia! I imagine you could cut it back a little bit, but despite the quantity called for here, it’s really not too sweet. Rhubarb is so tart, so it needs sugar to balance it out. Also, sugar does play a role in texture of cakes, so that’s something to keep in mind as well.
Could you swap out the rhubarb for any other fruit?
I haven’t tried, but I would imagine so … keep in mind that rhubarb is super tart, so you may need to cut the sugar back to make it work with other fruit.
I made this last night with thinly sliced blood oranges on top instead of rhubarb. Cut back the sugar from 1.5 to 1.25 cups. It was wonderful.
Wow, I bet that was gorgeous, too!
I really wanted this to work; but this is my second attempt, and it’s been in the oven for nearly 90 minutes (and I’ve doublechecked that the oven is heating correctly), and I can’t seem to get the temp higher than 195 or so.
I love the idea, but I’m a bit sad, having wasted nearly 2 lbs of rhubarb throughout both attempts.
And, note to others: I think my problem may have been that I reflexively put springform pans on a baking sheet in case of spillage, and that’s messing with the timing. If that’s your habit as well, then beware!
Bummer to hear this Paige. It sounds as though the baking sheet is causing an issue, but even so, 90 minutes seems like a really long time. Are you using an oven thermometer to check that the oven is heating correctly? If not, how are you checking?
Hi Alexandra,
I *am* using an oven thermometer — and according to it, the oven is heating correctly — but it does seem really strange, I grant you. I haven’t had much of a chance to bake this week, but I’m going to keep testing.
Ok, keep me posted! Sorry for the trouble … it’s no fun wasting ingredients.
Is it possible to refrigerate the batter in the pan overnight, then adding the rhubarb on top prior to baking?
I can’t say for sure because I haven’t tried specifically with this cake, but I’ve done this with other cakes, so I imagine it would work with this one. Go for it!
Made it, loved it. however, I had a problem getting it out of the springform pan, the bottom kinda stuck. Alexandra, any suggestions???
So happy to hear this! Bummer about the sticking. You could cut a round of parchment and stick that in the bottom of the pan. Were the sides OK?
Delicious, I would be happy to be served this in a restaurant or cafe.
🙂 🙂 🙂
Hi Alexandra ~~ While cruising around your web site your recipe for Rhubarb Custard Cake caught my eye. I had everything on hand except the rhubarb. After a bit of searching various markets, I did find it. Yay! I followed your recipe exactly, used my spring form pan, and it turned out WONDERFULLY!!! Had guests for dinner and they all scarfed it up and asked for the recipe. Thanks for sharing!
Yay!! So happy to hear this, Nancy. I love this one as well. So happy your guests approved. Hope you had a wonderful long weekend!
I LOVE this recipe! Total perfection
ME TOO! Saw it from you, first 🙂 🙂 🙂
Just made this! It’s little weird – I had to bake it for 90 mins, the top was not browning at all for the first 45 (this has never happened with other cakes and my oven). Also I feel like there was too much sugar and not enough rhubarb.. It’s still ok to eat but I think it can be a lot tastier! Can’t decide if I should try again with 1 1/4 cup sugar or not.
Also (and this probably is a matter of preference) sugar coating the pan just makes the cake stick not only to the pan, but also to the plate. Might try without.
Just made it again. Used more rhubarb, less sugar (1 1/4 cup), a pinch of salt more, and used parchment paper instead of buttering the spring pan directly. Cut rhubarb into smaller pieces and pushed them in a little. Baked for ~ 70 minutes and it turned out pretty good! Will make again 🙂
So happy to hear this, Kristine! Sorry to hear about the troubles the first time around. Glad your edits made for a better experience. Question: second time around, did you sugar the pan or coat it in flour? I hear you regarding the stickiness — part of the reason I do this, is because I never love the way coating in flour works for me … I find it always leaves a burnt-flour taste, whereas the sugar gets almost caramelized.
Third time making this recipe. It does look beautiful.Each time I’ve made as written with variations (no baking sheet under springform, moving it from lower to upper oven, light metal instead of dark metal pan). It’s almost really good, but every time the center remains approx. 190 degrees while the outer ring moves over the suggested 210 degrees. Not custardy enough, not cakey enough. Seems just kind of undercooked. My oven is accurate, I’ve baked it up to 18 minutes over the 45. Is this just the way it’s supposed to be? Feel like it should be better, but not sure what to change.
I’m so sorry to hear this, Katherine. I don’t really know how to advise because it sounds as though you’ve tried all the things to make it right. The texture of the cake isn’t necessarily custard-y the way a clafouti or creme brulee would be, but it’s definitely moist… it’s more cake-y than custard-y. Wish I could help more. I love this cake so much, but that doesn’t mean it’s for everyone. Sorry for the trouble.
I know this comment is a few years later, but perhaps Katherine or anyone else with the same experience could simply use a larger diameter springform pan to even out the baking and make it more cake-like. A larger surface area for the oven’s heat to get to would probably make it more evenly cooked all over.
I made this for the first time tonight, and it is so delicious! I used Bob’s Red Mill gluten-free all-purpose flour and vanilla extract instead of rum. My springform pan is larger than called for, making for a wider but more shallow cake. As others noted, this takes longer than 45 minutes to cook, even my wide, shallow cake. Who cares, though, it was sooo good! I will definitely make this again. What a treat for my gluten-free family!
So happy to hear this, Susan!!
what, if any adjustments might need to be made if using already frozen rhubarb already cut into pieces? concerned re: possibly too much moisture…?
Hi Mia! I might thaw the rhubarb in a colander to allow excess moisture to drain out. I don’t think I would make any other changes.
Hi, Mia, did you end up making the Rhubarb Custard Cake with frozen rhubarb? Dole makes frozen, cut rhubarb, and I have some in my freezer that I want to use to make this! So I also am wondering how it will turn out, if you made any adjustments, etc. Thanks if you have any suggestions or thoughts!
It’s delicious. I didn’t have rum or alcohol with me. So, I used to kithul treacle.
Oh yay! Wonderful to hear this.
Fabulous! I had chopped rhubarb on hand, and it worked perfectly. The cake was devoured by my family. Can’t wait to make it again. Thanks for the wonderful recipe.
Wonderful to hear this, Anne!
I’ve made this recipe 3 times this summer and it is foolproof. The substitution of vanilla extract for rum works perfectly.
Wonderful to hear this, Olivia!
This was delicious! I love the tip to sugar the pan-the resulting crust was one of my family’s favorite parts. This is one of those recipes I can see making and loving for years to come. Thank you!
So wonderful to hear this!! It’s one of my absolute faves!
For the rhubarb custard cake, would it work if I replaced rhubarb with sour cherries?
Hi Sol! Sour cherries sound absolutely delicious, and I think the sugar amount here would be plenty to balance out their tartness. I have never tried, so I can’t say it will work with certainty, but my gut is saying go for it 🙂
Ali, very good! I used mostly rhubarb but didn’t have enough so I added some raspberries too. And I used some vanilla sugar (100g) in place of the regular. And because I have a three year old helper I forgot completely the lemon zest. I don’t think I’m missing it though. Yum and Happy Spring Almost Summer!
So nice to hear this, Dana! This is my favorite 🙂
I made this today and it was excellent! Mine needed about 50-55 minutes in the oven. Good idea to sugar the pan because the edges caramelize beautifully. Served with lightly sweetened and salted whipped cream. Your site is becoming my go-to source for dinner and baking inspiration. Thank you!
So nice to hear this, Karen! I love the caramelized edge as well 🙂 Thanks for your kind words. Means a lot.
Gorgeous cake! The rhubarb is ready now in the spring garden. I was looking for a new recipe to try. Will be making this tomorrow. Hope mine turns out as beautiful as yours.
Great to hear this, Mia! This is one of my favorites. Hope you love it, too 🙂
This was superb! Dinner party guests raved about it, even one, a rhubarb hater, who was just taking a bite to be polite. The tip about sugaring the sides of the pan after buttering it is brilliant, and I will use it in the future. The cake took about 55 minutes to bake. Thanks for another winner, Ali!
So nice to hear all of this, Alyson! So glad you like the sugaring tip, too. I so prefer sugar to flour 🙂 And thanks for the note on the timing, too!
Hi Ali,
What a wonderful recipe and the sugared pan is essential. My bake time was a bit longer at approximately 60 ‘ but it came out perfect. The softer center combined with the crusty sugary edge was perfect.
I love that I keep exploring your blog and finding more and more true treasures.
All the best to you!
So nice to hear this, Bruce! And thank you for the kind words, as always. Truly means a lot 🙂 🙂 🙂
Back in rotation now that rhubarb is back! Delicious and the kids loved it – especially the sugar crust. Will definitely make for Mother’s day! Thanks Ali!
Great to hear, Marcie! I can’t wait for the rhubarb to start arriving at the market … haven’t seen any yet! Thanks for writing 🙂
Since I am on the West Coast I think we are a few weeks ahead of you all back east – hope you get some rhubarb soon!
Ali, can I use frozen rhubarb for this recipe? I live in Tx & we no longer get fresh rhubarb 😢
I would imagine you can! Have you used it before? And if so, did you use it frozen? Or did you thaw it first, let it drain, then use?
My husband this afternoon while the cake was in the oven, “why did you bake a cake? I don’t even like sweet things.” My husband this evening after two slices, “I’m sorry for what I said. This is incredible.” 😂 It was fun to bake and such a lovely mix of custardy and cakey and sweet and tart. My first time using rhubarb, and I’m obsessed. Also used sprouted spelt flour because that’s what I had and the subtle nutty notes are awesome!! No other changes and an extra 10 minutes in the oven. Thank you for sharing and for the notes! My rhubarb sunk too but I liked having it throughout the cake.
Awwww I love this so much 🙂 🙂 🙂 Sprouted spelt flour sounds so lovely! I can imagine how the nutty notes would pair so well with the rhubarb. Thanks so much for writing and sharing your notes!
Nice squidgy cake with lots of rhubarb and very sweet “custard-cake”. A few procedural tweaks–the recipe as written says flour–more for pan (we’re coating the pan with sugar, and next time I’ll add a parchment round as the cake really stuck to the bottom of the greased and sugared pan, esp given the texture of a springform pan bottom), and from an efficiency standpoint, step 1, turning on oven, preparing pan etc, should be done after step 2, during that 10 minute fridge rest. Finally, the “large” bowl needed to mix this all together is a bit excessive–medium bowl (8 cup batter bowl) gives you lots of room to whisk as the batter volume isn’t high. Not sure why we are folding in the flour though–I sifted mine but still found the folding a bit fussy—-left lumps that are more easily taken care of with a quick whisk.
Flavor wise, not sure lemon adds to rhubarb as much as ginger or orange does, so will sub next time. Also, the 2T rum didn’t come through at all (and I think it could add needed depth, so I will increase that a bit or if feeding adults, splash some over the top of the baked cake)
It was overall a good showcase for rhubarb but as it needed 3 bowls, and leaving an egg whit left over
Enjoyed this very much a few weeks ago and now have some even more ruby rhubarb. Do you have any thoughts on doubling?
Should work just fine doubling it! No need to make any other changes.
I have not made it yet, but was wondering if I could us frozen rhubarb? I get it from a friend in MN and I live in AZ so I freeze all mine to have through the year.
Same for the corn meal cake.
Thanks
I don’t see why it wouldn’t work… when it thaws, how is the texture? Still firm? Or does it get soft?