Rhubarb Custard Cake
This easy Rhubarb Custard Cake includes a touch of fresh lemon, with a dense, chewy exterior and soft custard-y inside. Lay the rhubarb across the batter in an eye-catching patchwork design – or keep it more simple, it’s up to you!
An Easy Rhubarb Cake Recipe
I’ve been making this Rhubarb Custard Cake every summer for a few years now, and it always gets big applause. It’s such a pretty dessert, with a hint of fresh lemon flavor to go along with the tart rhubarb!
This cake is easy to make. Mixed by hand, it bakes up with a dense, chewy exterior and soft custard-y inside. And you can lay the rhubarb across the batter in an eye-catching patchwork design – or keep it more simple, it’s up to you.
I always serve this rhubarb dessert with freshly whipped cream, which I think is utter perfection. But a scoop of vanilla ice cream would work well, too!
When I first saw this recipe in my copy of bon appetit magazine back in 2018, I immediately ripped it out. I was destined to make it. After eating my grandma’s rhubarb custard pie all my life, I was not going to pass up the opportunity to enjoy more custard desserts with rhubarb!
I haven’t altered this recipe much, have really only omitted the dark rum that was in the original recipe. But the one thing I have done is added some instructions and photos about how I add the patchwork of rhubarb across the top. Because I usually get asked just how it’s done!
Rhubarb Custard Cake Ingredients
This cake’s ingredients list is pretty basic. I LOVE the fresh lemon zest!
- Butter – You’ll need melted and cooled butter for the cake, plus a bit more for preparing the pan.
- Flour – For the cake batter and for preparing the cake pan.
- Baking powder – This gives a bit of rise and volume to the cake.
- kosher salt – A little bit of salt in a sweet dessert is always welcome!
- Eggs – Most custard desserts get their rich flavor and dense texture from egg yolks. This recipe calls for 2 eggs + 1 egg yolk.
- Sugar – This provides the sweet balance to the tart rhubarb and lemon. There’s some in the cake batter plus a bit sprinkled over the top for a subtle sparkle and added texture.
- Sour cream – This adds more dense texture and a light tangy flavor.
- Lemon zest – The bright lemon flavor is light and so very lovely!
- Rhubarb – The star of the show! I always lay the rhubarb in similar fashion to the original magazine photos, a patchwork design of rhubarb. So pretty!
How To Make It
No mixer required for this cake – you only needs your hands for some easy mixing! The end goal is a dense custard cake that doesn’t have extra air beaten into it.
- Preheat oven to 350° F and then butter & flour a 9″ springform pan.
- In a medium bowl, whisk together baking powder, salt, and 1 cup all-purpose flour.
- In a large bowl, vigorously whisk eggs, egg yolk, and sugar in a large bowl until very pale and thick, about 1 minute.
- In a small bowl, whisk melted butter, sour cream, and lemon zest.
- Whisk butter mixture into egg mixture. Then add dry ingredients and fold with a spatula until batter is smooth, and scrape into prepared pan.
- Place pan in refrigerator to chill for 10 minutes, to let the batter set.
- Arrange rhubarb over batter however you like, trimming as needed. To create the patchwork pattern you see in my photos, scroll down to see the tutorial photos in the post. Do not press the rhubarb into the batter; let it rest gently on the surface.
- Sprinkle with a little more sugar and bake until cake is golden on top and browned around the edges, about 45-55 minutes or so.
- Transfer pan to a wire rack and let cake cool in pan 10 minutes. Then slide a knife around sides of cake to loosen and unmold. Let cake cool completely.
How To Make The Rhubarb Design
When I make this cake, people often ask how I make the patchwork design of rhubarb on top. So here’s a few simple photos of what that looks like.
- Place a 9″ round cake pan upside-down. Then lay rhubarb stalks across the pan, in one direction. Trim the stalks about 1″ shorter than the length across the pan.
- Cut all the rhubarb stalks in half, right down the middle.
- Rearrange two opposite quarters of the rhubarb, positioning them vertically now, for a patchwork design.
- Gently transfer cut rhubarb to the top of the chilled cake batter – do not press the stalks into the batter. Leave some batter showing in between each stalk, trimming the stalks more if needed. You might not use all the rhubarb that you cut for this pattern.
Tips For Rhubarb Custard Cake Success
Here are a few helpful tips for making this cake.
- Let butter cool. After melting the butter, let it cool completely. This will help the batter to be cool and firm, so the rhubarb doesn’t sink into the batter.
- Hand mix the batter. This cake is meant to be dense, so mixing the final batter with a gentle hand is best. An electric mixer will work more air into the cake, which is not what we want here.
- Chill the batter. After transferring the finished cake batter to the pan, place the pan in the fridge to chill for 10 minutes. This helps to firm up the batter – again, so the rhubarb doesn’t sink.
- Sprinkle additional sugar. Some might be tempted to skip the last bit of sugar that is sprinkled over the cake batter, but it gives a lovely additional texture plus a touch of sparkle!
How To Serve
I like to serve this easy rhubarb cake the same day it’s baked, at room temperature or just the slightest bit warm. I think this lets the different textures of the cake shine through, with a dense, chewy exterior and soft custard-y inside.
And I always, always, ALWAYS serve this cake with homemade whipped cream, just lightly sweetened. It’s perfection, in my opinion.
But for those of you who like ice cream more, a scoop of vanilla ice cream would also be delicious!
Can I Make This In Advance?
While I prefer to bake this cake the day I serve it, I do think this is a dessert that can be made a day in advance if necessary. You will lose some of the sugary crispness on the cake’s exterior, though.
Store the completely cooled cake in an airtight container in the fridge, then take it out of the fridge and let it come to room temperature prior to serving.
How To Store Leftovers
Store any leftover cake in an airtight container in the refrigerator for up to 3 days.
More Dessert Recipes with Rhubarb
- Strawberry Rhubarb Crisp – a top reader favorite!
- Rhubarb Sour Cream Coffee Cake
- Rhubarb Custard Pie – my grandma’s recipe!
- Rhubarb Cream Cheese Bars
- Rhubarb Sauce – so easy!!!!
- Strawberry Rhubarb Crumb Bars
- Rhubarb Cheesecake Pie
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Ingredients
- 4 tablespoons melted unsalted butter completely cooled, plus more butter at room temperature for the pan
- 1 cup all-purpose flour plus more for the pan
- ¾ teaspoon baking powder
- ½ teaspoon kosher salt
- 2 large eggs
- 1 large egg yolk
- 1½ cups sugar plus 1 tablespoon for sprinkling over the top
- ¼ cup sour cream
- 2 teaspoons finely grated lemon zest
- 13 ounces rhubarb stalks – I like to use thin stalks that are red but slice them in half lengthwise if you have thick stalks
Instructions
- Preheat oven to 350° F. Butter and flour a 9" springform pan, and set aside.
- In a medium bowl, whisk together baking powder, salt, and 1 cup all-purpose flour.
- In a large bowl, vigorously whisk eggs, egg yolk, and 1½ cups sugar in a large bowl until very pale and thick, about 1 minute.
- In a small bowl, whisk melted butter, sour cream, and lemon zest.
- Whisk butter mixture into egg mixture, just to combine. Then add dry ingredients and fold with a spatula until batter is smooth, and scrape into prepared pan. Place in refrigerator to chill for 10 minutes, to let the batter set.
- Arrange rhubarb over batter however you like, trimming as needed. To create the patchwork pattern you see in my photos, refer to the tutorial photos in the post. Do not press the rhubarb into the batter, let it rest gently on the surface.
- Sprinkle with 1 tablespoon of sugar and bake until cake is golden on top and browned around the edges, about 45-55 minutes or so. Transfer pan to a wire rack and let cake cool in pan 10 minutes. Then slide a knife around sides of cake to loosen and unmold. Let cake cool completely. Slice into individual pieces and serve with whipped cream if desired.
Notes
Nutrition Information:
So glad your brought this over the 4th of July. Rhubarb custard is a favorite of mine, and the touch of lemon is delightful.
I knew you’d love it. :) xo
5 stars