Cast Iron

Rhubarb Upside-Down Cake

March 13, 2021
5 Ratings
Photo by Eric Moran
  • Prep time 30 minutes
  • Cook time 45 minutes
  • Serves 8 to 10
Author Notes

Melt rhubarb, butter, sugar together in a cast iron skillet, then lay down clumps of sturdy dough onto the warm fruit, less like a blanket and more like a dowdy, misshapen comforter. It will feel a lot like a cobbler, and you’ll worry you’re doing something wrong. Put it in the oven.

The cake’s baking soda will pinch hit, making the batter rise on up to cover any spots of rhubarb you may have missed. (In this way, it’s like a tarte tatin you can’t mess up.) It will grow into a cake. Say a quick prayer and flip it upside-down. You’ll wonder again, briefly, if this is actually a cobbler. Trust it.

What you’ll reveal is an underside that’s a mess of girlishly pink, warm rhubarb jam perched smugly on top of a buttery crumb. "Did you think I wasn’t going to work?" it’ll coo.

This recipe is adapted from Saveur. —Kenzi Wilbur

What You'll Need
  • 1 1/2 cups sugar, divided
  • 4 tablespoons unsalted butter, plus 1 stick and 6 tablespoons cut into 1/2-inch cubes and chilled
  • Zest of one lemon
  • 1 tablespoon plus 2 teaspoons fresh lemon juice
  • 2 teaspoons vanilla extract
  • 1/2 teaspoon kosher salt, divided
  • Scant 1 pound rhubarb, trimmed and cut into 1-inch pieces
  • 2 1/2 cups all-purpose flour
  • 2 teaspoons baking powder
  • 1/3 cup whole milk
  • 2 eggs, lightly beaten
  • Ice cream or whipped cream for serving, optional
  1. Heat oven to 375° F. Melt 1 cup of the sugar, 4 tablespoons butter, lemon zest and juice, vanilla, and 1/4 teaspoon of salt in a 9-inch cast iron skillet over medium heat. When the butter and sugar have melted together, add the rhubarb pieces and cook, stirring occasionally, until rhubarb is tender and slightly caramelized, 6 to 8 minutes, depending on the thickness of your rhubarb stalks.
  2. Meanwhile, whisk together remaining sugar and salt, plus flour and baking powder in a bowl. Add remaining butter, and using your fingers, rub into flour mixture to form coarse pea-size pieces. Like Phyllis Grant would say, make like you’re snapping your fingers. Add milk and eggs and stir until a soft, sticky dough forms. If your eggs are on the small side, you may need an extra splash of milk for the dough to come together.
  3. Place pieces of dough over the hot rhubarb mixture, trying to cover the entire surface. It will feel a little like you’re making a cobbler, but the dough will rise up and fill in any holes you’ve left. Bake on a baking sheet until the cake is golden and cooked through, about 30 to 35 minutes. Remove skillet from oven and let the cake rest for about 10 minutes. Place a large, flat serving platter on top of the skillet and invert quickly and carefully. Serve warm or at room temperature with ice cream or whipped cream, if you like, but it’s just as good plain.

See what other Food52ers are saying.

  • manitouanne
  • kumalavula
  • helicopterina
  • Diane
  • tantesophie

44 Reviews

BR95510 May 26, 2021
I agree with some of the others. Far too much topping. Could be reduced by 25% at least. I'll also make it thinner next time. If it's thick and dry going in the pan, it's going to come out thick and dry after baking. I used less sugar in the rhubarb; I like the tartness, but I'll add some cinnamon and about a 1/4 tsp of nutmeg also. A 1/4 tsp of nutmeg to the cake batter would be good too.
Janet August 12, 2019
I thought it was fantastic! I added strawberries to the rhubarb because my husband won't eat "just"rhubarb and the results were wonderful. I also didn't have whole milk and 2% worked fine. I may add a touch of cinnamon or ginger to the cake but it was quite delish as it was! I loved the way the clumps almost formed individual servings after it turned out. My baking time was less as well but I just watch it because my oven is whackadoodle. It was crunchy on top ( bottom ) and wonderfully moist inside. the Fruit topping was heavenly! Can't wait to have some for breakfast with a Cuppa
manitouanne May 23, 2017
This recipe works fine however my guests and I agreed too much cake to rhubarb. Back to pie for us to let the tangy rhubarb be the star of the desert.
kumalavula April 29, 2017
i left the rhubarb to caramelize for longer than the recipe suggested. it smelled divine as i was making the dough. turns out i had more dough than i needed and didn't want it to be overly doughy as it baked so i used enough to cover 95% of the rhubarb and allowed for the baking powder to do its job of rising and filling in the gaps. otherwise i followed the recipe almost exactly. so glad to have this recipe. the rhubarb is growing like crazy and between this and my homemade rhubarb vanilla preserves, that poor plant is going to be growing as fast as i can cut its stalks this season. thanks for such a tasty recipe idea.
helicopterina June 4, 2016
This looks great - do you think I could make it the evening before serving it at brunch? Or best to wait and do it same day? Thanks !
tantesophie June 4, 2016
Absolutely ... I would serve it at room temperature to get the most flavor rather than disguising it chilled ... might as well get work done the day before so you can enjoy the brunch!!!
helicopterina June 7, 2016
Thanks, tantesophie !
MB M. May 31, 2016
Made this yesterday and the cake came out quite dry. Only baked for 30 minutes, too. Ended up picking more than 1 lb of rhubarb, and used the extra to make sauce served on the side to help abate the dryness.
Amanda H. May 31, 2016
Hi MB Martini, I'm wondering if your oven runs a little hot? Or did you use a non-stick (or dark-coated) pan? If so, this will affect the baking time.
cass August 31, 2015
Could I use a 10 inch cast iron pan- don't have a nine inch one?
tantesophie August 31, 2015
Absolutely ... mine is 9.5" on the bottom inside and 10.5" on the top edge ... bake it!!!
Diane May 26, 2015
Got rave reviews from my dinner guests when served with a little sweetened whipped cream. Used a mini food processor to cut in the butter (in two batches). I was too lazy to do it by hand or to drag out the big, heavy 35 year-old Cuisinart! Next time, I will reduce the quantity of butter a little bit. Seemed a bit heavy on the butter.
tantesophie May 25, 2015
Just made this for dessert tonight ... AMAZING ... the best rhubarb cake EVER ... had a bit more than a pound of rhubarb from the first harvest in the garden ... hey ... just put it all in and didn't look back ... go bake a rhubarb cake!!!
Valeria P. May 22, 2015
Very nice simple recipe, but the cake came out way too sweet! I'll definitely try it again with just 1 cup of sugar.
Tina W. June 23, 2014
This was absolutely delicious. I added a sprinkling of cinnamon and nutmeg to the cake batter. Thanks for such an awesome recipe!
Hold T. June 17, 2014
Would skim milk work?
monacake June 16, 2014
i didn't change this recipe a bit and it came out lovely and delicious. the cake had a firm and moist crumb, and the fruit was a nice balance of sweet and tart. nice to have rhubarb stand on it's own without strawberry muddying the flavor. i wouldn't change a thing.
Gmarkb June 7, 2014
Any risk of adding some strawberries to the rhubarb?
Horto June 6, 2014
reduced the sugar to just one cup, this better be good!and butter as well
Lynn June 4, 2014
Lol I just re-read the recipe and found I made a mistake, but I have to say the mistake wasn't even an issue. Instead of using 1 stick plus 6 tablespoons of butter for the topping, I used only 4 TBS total. The result of delicious. So, if you want to use less butter go ahead! Loved this recipe.
Awads May 29, 2014
oh, i should add: i wound up making an extra batch of the rhubarb topping, to pour over ice cream. we had a gluten-intolerant guest and i didn't want him to miss out on all the rhubarb deliciousness! i can't wait to make the cake again.
LauriL May 29, 2014
It was as predicted....amazingly yummy! Never too much butter says my palate!!
AP May 28, 2014
Well I had high hopes!
Way too sweet, the vanilla does not go with the rhubarb!
Really a ton of butter. After tasting I threw the whole thing out.
zahavah May 27, 2014
After I caramelized the rhubarb, I was left with over a cup of syrup. Are you supposed to have this much? I'm thinking of doubling the rhubarb and halving the sugar and butter. Thoughts?
Kenzi W. May 27, 2014
You are supposed to, yes! Lay the dough over the top, and the syrup will thicken and seep into the cake as it bakes.
zahavah May 27, 2014
Thanks Kenzi!