This cake is designed to be mixed by hand. Using an electric mixer works more air into the eggs, which lightens the batter and makes it less dense, so the fruit is more prone to sinking. Also, make sure you leave the stalks whole, as chopped rhubarb is more likely to be swallowed up by the batter and sink to the bottom.
4 Tbsp. melted unsalted butter, cooled, plus more room-temperature for pan
1 cup all-purpose flour, plus more for pan
1½ cups sugar, plus more for sprinkling
2 tsp. finely grated lemon zest
13 oz. rhubarb stalks, halved lengthwise if thick
Preheat oven to 350°. Butter and flour pan. Whisk baking powder, salt, and 1 cup all-purpose flour in a medium bowl. Whisk 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 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. Sprinkle with more sugar and bake until cake is golden on top and browned around the sides, 45–55 minutes. 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.
Do Ahead: Cake can be baked 1 day ahead. Store tightly wrapped at room temperature.
Reviews SectionThis recipe is amazing. Chewy on top and soft in the middle and still allows the tart rhubarb to really shine through. This recipe will definitely be one I go back to in late spring when the rhubarb is bountifulThis cake is the bomb. I make it multiple times a summer and it makes all of us happy every time. I'm going to try making it with plums and sour apples this year.This is a lovely dessert. The rhubarb softens more than one would expect, so cutting isn't hard. I wasn't sure why it is a custard cake, but it must be the rhubarb juice making the cake nearby just the slightest bit custardy. It's so festive. I liked it still slightly warm.AnonymousNorwich VT06/13/20Super yummy! I replaced the sour cream with greek yoghurt, and I added 1 cup instead of 1.5 cups of sugar based on other reviews. It turned out great! I will however next time sprinkle on more sugar on top of the cake and rhubarb before putting it in the oven. The rhubarb was a little too tangy.Rhubarb is back at the market!! I made this cake for a second time and it was a huge hit. I'm not usually a rhubarb (or even much of a baked fruit) gal but this hits the spot.I didn't make any changes to sugar (I have a sweet tooth but didn't think this was overly sweet as is..) and I cut my rhubarb in ~1-2in pieces and in half lengthwise because they were pretty thick. I let is set in the fridge for about 25 mins and the rhubarb didn't sink at all after baking! My springform was a 10" sadly so it was a bit thinner but still dense and moist and delicious.I wonder if it would benefit from switching the sour cream for mascarpone? Things to try next time...This is my go-to recipe come Rhubarb season, and my favorite to recommend to others. Its got basic ingredients I always have on hand, and turns out wonderfully each time. Easy to make and a crowd pleaser every time - can't go wrong, right? :)cchasteenMinneapolis St Paul Minnesota USA05/24/20Super yummy! Based on other reviews, I only added 1 cup of sugar instead of 1.5 cups. I was okay with my rhubarb falling so I chopped it into bit sized pieces so it would be easier to eat. I also diced some strawberries I had and used those as well. There was some very slight falling by both fruits, but overall it looked beautiful. I like lemon flavored things and this wasn't overpoweringly lemony, but I think next time I may only use 1 tsp of lemon zest so the flavor is more subtle. It was the perfect light treat to have after a big grill out!AnonymousNebraska05/24/20I made this and while she tastes beautiful for some reason it like barely rose at all? and also weirdly the batter barely filled the pan? any ideas why this might have happened? it's great and so springy but wondering if anyone had this problem also!I’ve made this five times now - it’s amazing. I reduced the sugar by a half cup and and finely chopped some rhubarb to put on top and let sink in before adding the long pieces on top. Love having rhubarb in every bite! Also did one with some slivered honey almonds on top. This is a winner recipe with a lot of versatility. 👏🏻👏🏻👏🏻👏🏻👏🏻@thebirdsnestKoppertop75Middleton, WI05/21/20This cake is DELICIOUS. I didn't have any dark rum, so I used vanilla extract and lemon juice to make up the 2T of liquid. I also realized after pouring the batter in the pan that I used a 10" springform pan rather than the 9" one called for. I baked it for about 35 minutes and it came out perfect anyway! Will make it every rhubarb season for sure.After translating the measurements into metric i can say this recipe is really lovely i replaced the dark rum with some licor 43 as it was the only thing i had on hand and the sour cream with some creme fraiche. It is so good.This was so delicious! I wish I could have more people over to try it out. The texture is really interesting. The outer edge is a bit crunchy and chewy and then the inside is a little gooey like pudding but also firm. Very hard to explain but I really liked it.My only change would be to lessen the sugar a bit. It was a nice contrast from the tart rhubarb but a bit too sweet for my liking.Also super easy to make! I'll make this again.Oh and for the person below: No my rhubarb didn't get smooshed down when I cut into it but I used a serrated knife.Fabulous snacking cake with a balance of tart and sweet. I made a few minor adjustments:-substituted 1/2c of flour with almond meal-only added 3/4c sugar (a blend of brown & white). I like my cakes on the not-too sweet side.-instead of rum, used 1T of anisette liquor (I ran out of rum!)-instead of sour cream, used plain yogurt-skipped the sprinkled sugar on topFollowed the instructions as stated (hand whipped only; chilled in the fridge for 10mins) and the batter was sufficiently thick that all my rhubarb stayed on top. I scatted a mix of small pieces of rhubarb and skinny batons. Definitely err on the small cuts of rhubarb so it's easier to eat. Baked for about 50mins, the bottom and edges were golden brown, and the cake just below the rhubarb was slightly custardy.Easy recipe without having to cream butter, whip egg whites, etc. I had two dirty bowls at the end, and with the exception of the rhubarb, typically have all the ingredients ready at hand. Yum!This is one of my favorites!!I make it with gluten free flour. It’s delicious even if you don’t like rhubarb!jeremyryanbColumbus, Ohio05/16/20Delicious! I used spelt flour and Greek yoghurt, as that's what I had. The rhubarb sank a little, perhaps because of the yoghurt, but it tasted amazing regardless. No one could taste the rum as such without knowing it was in there, but it gave a lovely additional flavour. I'll be making this again and again for an easy dessert.GeorgiePieGermany05/15/20Just made this a second time and wanted to comment to say: You can definitely make this without a springform pan. I cut parchment paper a few inches bigger than a regular cake pan, sprayed it with PAM, and then pulled the cake out by the parchment paper edges when it was done resting for 10 min. LOVE THIS CAKE, CLAIRE!alexbeggsBon Appétit 05/11/20Made this tonight - followed the recipe exactly except for swapping rum for whiskey because that's all I had. It was so delightful and looks absolutely beautiful. I cut my rhubarb slices in half lengthwise because they were a bit thick, and they sank a tiny bit but still looked really pretty on top. It's a great cake and uses ingredients I usually have on hand (other than rhubarb) so it's a keeper recipe for sure. Can't wait to share it with friends after quarantine is over.Easy, so delicious, and doesn’t make too much for 2 people quarantining. I accidentally used the ⅓ cup measure for flour, but the extra flour probably helped with the rhubarb not sinking. I reduced the sugar to ½ cup, which the perfect amount of sweetness.I used a package of frozen chopped rhubarb, and used sambucca instead of rum for flavouring.It was absolutely delicious.I'd love to make this cake, but am wondering how tender the rhubarb gets and how easy it is to cut the pieces in the finished cake?I have made this cake a dozen or so times since I found it. It's one of my favorite and so easy to throw together (I generally have everything on hand at all times except the rhubarb), so perfect for when I need something relatively quick.I always have followed the instructions to a t and have never had the issue of sinking or not being cooked through.The only change I have ever made is the liquor depending on what I have on hand and I use vanilla sugar on top.This is delicious, easy, and super pretty. Always a great way to end a meal (or start your day)!gik910Chicago, IL08/10/19Cut the rhubarb up into bit sized pieces--rhubarb is stringy...jessica.jackson8460422Denver06/28/19Now that I’m reading the reviews after I made the cake, I agree that I will use less sugar next time. With the tart rhubarb (which is my reason for wanting this cake) only on top, it is overpowered by the sweetness of the cake. And I will cut the rhubarb pieces smaller for ease of serving and eating.I did not need to bake mine longer. In fact, I forgot to put sugar on top of mind so it did not brown readily and I left in in for full 55 minutes which I think was too long as the bottoms and desired were overdone.This is a very dense cake that I do not think keeps well for a day. I don’t know if whisking more or less would have remedied it. It’s a dessert that’s not full-on custard; having the hint of cake wants it act more like more cake. Although I think I want it to be more custard-like.AnonymousSt. Paul, MN06/10/19This is a super easy, great little cake. I read the reviews before making it and hand whisked everything (per the recipe instructions), and the cake turned out perfectly. The rhubarb didn’t sink and the cake was still fairly light. If you absolutely must use your mixer, I would make sure the speed is low to avoid adding too much air to the mixture. I cut the rhubarb into small pieces (around 1” on a diagonal) which was great with regards to cutting and eating the cake. Also, I only had about 7 ounces of rhubarb and it was perfectly fine, but I do think it would have been better if the cake was totally covered so you get rhubarb in every bite.Made this tonight and everyone enjoyed it. I mixed by hand and cut rhubarb in half lengthwise but still had some sinking. I recommend using thin short stalks as pictured. I used 1/4 cup less sugar and subbed 1 tbs amaretto and vanilla for rum since I don’t like rum flavor.Aswini PadmanabhanCalifornia 05/28/19
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