What I love about This Rhubarb Cake!
- In this flourless, upside-down rhubarb cake, I resisted the temptation to add berries or other fruit, to highlight the rhubarb’s true flavor. The bright liveliness of the rhubarb is front and center, the sourness mellowed slightly with vanilla and butter, while the base of the cake, made entirely of almond meal and no flour, whispers of cardamon. To my palate, the combination delights.
- The cake is totally grain-free.
- If you rather not do it upside-down, you can do it right-side up. See recipe notes.
How to make Rhubarb Cake
Once the rhubarb is cooked, set it aside, leaving it in the cast-iron skillet. Drain off half of the syrup and set aside. We will bake the cake in the skillet.
Tip: If your rhubarb is not very colorful ( your stems are green) you can always add a some berries to give this some color.
Step four: In a stand mixer, whip egg whites on medium high speed, and once you see bubbles, add a pinch of salt and a teaspoon of vinegar . Whip until egg whites have formed soft peaks, then add remaining ¼ cup of sugar a little at a time whipping until medium stiff peaks form. Turn speed down to medium-low and begin spooning in the flour/egg mixture , a heaping spoonful at a time, into the egg whites until it is all combined, scraping down sides as necessary.
Step five: Pour batter over drained rhubarb in the skillet and place in a preheated oven, for 30-40 minutes. While baking, make sure to have ready, what you plan to flip the cake on to.
NOTE: Alternatively, you can also pour the batter into a greased 9-10 inch cake pan and top it with the rhubarb (instead of doing the upsidedown version).
More Rhubarb recipes you may like!
- Rhubarb Muffins
- Rhubarb Crisp
- Baked Salmon with Rhubarb
- Rhubarb Shrub Recipe!
- Rhubarb Tart with Lemon, Cardamom & Vanilla
- Strawberry Rhubarb Cobbler
- Recipes to Celebrate Spring!
Rhubarb Cake
- Prep Time: 20 mins
- Cook Time: 40 mins
- Total Time: 50 mins
- Yield: 8 1x
- Category: Dessert, cake
- Method: baked
- Cuisine: American
- Diet: Gluten Free
Description
This upside-down Rhubarb Cake is baked in a cast iron skillet. It’s gluten-free- and grain free- made with Almond Flour. Deliciously addictive and perfect for Spring.
Ingredients
- 4 cups rhubarb, cut into 1/2-inch cubes ( about 1 1/4 lb) Use red pieces for best presentation.
- 1 1/4 cup sugar -divided (or use half brown sugar)
- 4 tbsp butter
- 1 tablespoon fresh lemon juice
- 2 tsp vanilla extract
- pinch salt
- 4 eggs, separated into 4 egg yolks and 4 egg whites, room temperature
- zest from one lemon
- 1/4 teaspoon cardamon
- 1 1/2 cups finely ground almond flour or meal
- 1 teaspoon baking powder
- 1 teaspoon white or cider vinegar
- Powdered sugar for sprinkling
Instructions
- 375 F Oven
- Over medium heat, melt butter in a 9-inch cast iron skillet and brush the sides with it. Add rhubarb, ¾ C sugar, lemon juice, vanilla and pinch salt and stir for 2 minutes, just until combined and sugar has dissolved. Turn heat off. Do not continue to cook rhubarb. Drain off half of the syrup and set aside.
- In a medium bowl, whisk egg yolks with lemon zest, cardamon and ¼ cup sugar, until creamy and sugar has dissolved. Set aside. In a small bowl, whisk almond flour, pinch salt, and baking powder until combined. Add flour mixture to egg mixture and stir to incorporate. You will have a very thick heavy batter at this point.
- In a stand mixer, whip egg whites on medium high speed, and once you see bubbles, add a pinch of salt and a teaspoon of vinegar . Whip until egg whites have formed soft peaks, then add remaining ¼ cup of sugar a little at a time whipping until medium stiff peaks form.
- Turn speed down to medium-low and begin spooning in the flour/egg mixture , a heaping spoonful at a time, into the egg whites until it is all combined, scraping down sides as necessary.
- Arrange the rhubarb evenly on the bottom of the skillet, remembering this will be the top of the dessert. Pour batter over the rhubarb in the skillet and place in a preheated oven, for 30-40 minutes. (While baking, make sure to have a plate or platter ready, what you plan to flip the cake on to.) At 30 minutes, check for doneness by inserting a toothpick or skewer into the middle of the cake. If it comes out clean, it is done. If not, bake a bit longer.
- Pull from the oven, let it stand 5 minutes, and run a knife along the edges. Place a cake platter or cake stand over the skillet, and invert, gently tapping the bottom of the skillet so it releases.
- Let stand 10 minutes. Poke holes in outer edges of the cake (skip the middle area) and drizzle with reserved rhubarb syrup if you like.
- Serve with vanilla ice cream or on its own. The cake is especially good the next day.
Notes
I use a 9-inch cast iron skillet for this recipe! I’ve also tried it with a 9-inch spring form pan- with no leaks- but some readers have had issues with leaks. So, warning! If using a spring form pan, line the bottom with parchment and bake over a sheet pan.
Feel free to add almond extract, more almond flavor.
Nutrition
- Serving Size:
- Calories: 350
- Sugar: 22.4 g
- Sodium: 220.7 mg
- Fat: 15.2 g
- Saturated Fat: 3.6 g
- Carbohydrates: 28.5 g
- Fiber: 1.8 g
- Protein: 6.5 g
- Cholesterol: 72.2 mg
Delicious! I just made this tonight. I used oat flour instead of almond, 1/4 t of baking soda instead of powder. It’s spongy and firm, great texture. The rhubarb is just the right sweetness! The only challenge was inverting it onto a plate because the cast iron is so heavy haha. Thanks so much, got my new go-to recipe!
Awesome Johanna! glad this worked for you!
This is a delish cake. I make it every year when rhubarb is in season. Did you change the recipe? Both times this year when I’ve made it the batter has been much more liquidy than in years past, and it’s overflowed the pan both times. Is using honey/shrup instead of sugar new? Cake tastes delish, but it’s definitely different this year.
Hi Sara- yes I have been fiddling with it. I just restored it to the original recipe and I am sorry about this- I was trying to make the recipe easier.
I’m glad I read your response that you are tweaking the recipe – I didn’t remember pouring out part of the syrup in the pan, is that different too? Regardless, this is such a delish recipe and is one of our family’s favorites!
Yes, I changed that part because some were saying the cake was too soggy. I think pouring it off helps and you can always drizzle it over the cake after it’s flipped.
As usual another one of your recipe HITS! I love this so much. I had organic almonds on hand that I ground into flour and fresh rhubarb from the garden, I will make this instead of rhubarb pie from now on! The flip was simple, I think this is a very pretty desert, good enough for company and impressive too!
So happy you enjoyed this Faye!
Quick emergency! Ingredients indicate baking soda; directions refer to baking powder. Which is correct? Making this now for a party!
Sorry Catherine! It is baking soda- fixed the instructions.
Incredible!!! The rhubarb just melts in your mouth 😋 My friend keeps giving me rhubarb from her garden, and thank goodness for your recipes! The flip went smoothly and my belly is really happy 🙂 thank you Sylvia!
Oh Good Angeli! People have had issues with the recipe – I am so glad it worked for you! Did you use a cast iron skillet?
Yes! I used a seasoned cast iron skillet and buttered it like you said 😊
Ok great to hear! Thanks for confirming. 🙂
Good flavor, but not incredible.
I had no problem with the cake holding shape when I turned it onto a platter. That being said, a huge amount of juice flowed out of the pan all over my counter when I did so (yes, I followed the recipe exactly). In contradistinction to being “even better on day 2,” on day 2 the base was soggy and unappetizing. Our chickens appreciated the remaining cake.
Oh no! Sorry about that Mary. When making it, did your batter seem thick?
Yes, very. I wondered how it was ever going to incorporate into the egg whites
Hummm, ok. It sounds like the cake was ok, but maybe the rhubarb top was a little too juicy. I will remake this and update the recipe. Thanks Mary.
Recipe list states baking powder but written recipe says baking soda?? Which one is it??
Sorry Sara! Baking powder. Thanks and updated the instructions. 🙂
question – do you need to refrigerate the cake after cooled for next day enjoyment?
You can Jessica, but I usually just leave it out on the counter, lightly covered- it is fine for a few days.
Yummy! It came right out of my cast iron pan with no problem. Almond flour cakes are sometimes delicate, and this one was. It’s not pretty enough for company, but for my husband and I, it’s perfect! Maybe a smaller cast iron would have worked better. Yours looks beautiful and mine, not so much. My rhubarb cooked up brown-ish as well, and your’s is red. But it tastes divine,and isn’t that all that counts
So happy you enjoyed this Alene. For the photos, I purposely sought out the reddest rhubarb stalks I could find.
Absolutely delicious flavor, but the rhubarb part was way too juicy, and it came out like oatmeal with a rhubarb sauce. I also used a sugar alternative (monk fruit) as I am diabetic. I would try making this again, but I think I would add some tapioca flour to the rhubarb ingredients to thicken it. And I would probably bake it a bit longer next time!
I really think it is the sugar substitute making it more juicy. I’m not positive, but it’s my best guess. 😉
Loved this recipe! the flavor was great and my gluten-free friends enjoyed it. Can this recipe be modified to us standard flour? At times I run out of almond flour and my immediate family doesnt have gluten issues.
You know, great question Ann and I’m not sure! I think it should work?? But not positive. 😉
Hello I am not going to rate the recipe, because I believe it failed due to my substitution of Swerve for the sugar. My daughter cannot have sugar while she is on her current diet. I used the exact amount (as the Swerve package states that substitution for sugar is 1:1) and my fresh rhubarb seemed to release A LOT of liquid (much more than your photo), however I didn’t drain it, as I would have removed the Swerve. Not sure if the excess liquid was due to my extra juicy rhubarb, freshly picked from my garden, or using the Swerve. The cake portion rose and baked beautifully, but it soaked up all the liquid. Although the cake surprisingly maintained it’s structure, it was very soggy – like a sweet, wet sponge! So perhaps I will try again subbing the sugar with honey (as she can have a little of that).
Oh shoot Robin! Yes not sure about the Swerve- I have never used it, so not sure how it works in recipes? I use fresh rhubarb here as well-it does get juicy, but not overly, so don’t think it was that? Appreciate you sharing this, maybe useful to someone else out there!
A hit! Could not find ruhbarb, used fresh picked blueberries. It wAs a treat!!!
Nice Katey! Yum fresh blueberries, that sounds amazing.
Deeelucious light and tasty. I baked the rhubarb in a round metal non stick cake pan with the butter in the oven until it bubbled and it worked perfectly.
Wonderful to hear Diane!
I wish that I had printed this recipe before the changes were made to it. I make it in a regular cake pan, without the fruit, topping it with a maple glaze instead.
Hi Beth, the recipe itself has not changed- only the pan. It use to have a spring form pan option, but people were having issues with it leaking. A cake pan should work great!