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This Rhubarb Cake is gluten-free, grain-free, made with Almond Flour. Deliciously addictive, perfect for Spring! Make it upside-down or right-side up, your choice!
It is the giving of attention – that keeps us awake.
I love this recipe for Rhubarb Cake! In Spring, one of the first things to poke their arms out of the ground is the rosy-colored stalks of rhubarb. They surprisingly have many uses in the kitchen- but what they are known for most is pie. Rhubarb is also called the “pie plant”- and paired with strawberries, berries, or apples, rhubarb is often thought of as a fruit – but in actuality, rhubarb is a vegetable in the same family as sorrel. It actually tastes sour, alot like sorrel.
Rhubarb’s flavor and aroma hint of tart apples, berries, and more subtler notes of water and fresh green grass.
Tip: Always remember Rhubarb “greens” are toxic, always use the stems only, never the greens.
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
It starts with four cups of fresh rhubarb, cut into ½ inch cubes.
TIP: Choose the reddest rhubarb pieces you can find for the best presentation!
Step One: In a heavy bottom skillet, melt butter, and add rhubarb, sugar, lemon juice and vanilla. Stir until combined and sugar has dissolved, but do not cook the rhubarb through, it will cook in the oven. Also, this is the only “fat” in the cake, so I don’t recommend cutting back, the butter will seep into the cake and it is tasty. 🙂
Once the rhubarb is cooked, set it aside, leaving it in the cast-iron skillet. We will bake the cake in this!
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 Two: Make the cake batter. In a large bowl, whisk the eggs, olive oil, honey or maple and vanilla. Add the lemon juice and lemon zest, cardamom and salt. Ready your baking pan.
Whisk in the baking soda until fully incorporated, then whisk in the almond flour.
Step three: Pour the cake batter over the rhubarb.
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).
Step four: Bake in a 350 F oven on the middle or lower rack, for 30-45 minutes or until puffed in the center and golden, and a toothpick comes out clean. Pull it out.
Step five: Let is stand 5 minutes, run and knife along the edges and invert onto a platter. Sprinkle with powdered sugar. Let it stand 10-15 minutes before cutting to let it set.
Serve with vanilla ice cream or whipped cream.
Enjoy the cake! You can leave it out on the counter, covered for 4 days, though I doubt it will last that long. 😉
xoxo
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
Units
Scale
Rhubarb Topping
- 4 cups rhubarb, cut into 1/2 inch cubes (try to use red parts for the prettiest presentation)
- 3/4 cup sugar
- 3 tablespoons butter
- 1 teaspoon fresh lemon juice
- 1 teaspoon vanilla
- pinch salt
Almond Flour Cake
- 4 eggs
- 1/4 cup olive oil
- 3/4 cup real maple syrup, agave syrup or honey
- zest from one lemon
- 1/4 cup lemon juice
- 2 teaspoons vanilla
- 1/2 teaspoon cardamon
- pinch salt
- 1 teaspoon baking soda
- 3 cups finely ground almond flour (360 grams, or 12.5 ounces)
Instructions
- Preheat oven to 350 F
- Over medium heat, melt butter into a well-seasoned, 9-10 inch cast iron skillet, and brush the sides with it. Add rhubarb, 1/2 cup sugar, lemon juice, vanilla and pinch salt and simmer for 2-3 minutes, just until combined and sugar has dissolved. Turn the heat off. Do not cook rhubarb all the way through.
- In a medium bowl, whisk the eggs with olive oil and honey. Add the lemon juice, lemon zest, vanilla, and cardamon, and salt.
- Whisk in the baking powder and the almond flour a little at a time. You will have a very sticky batter at this point.
- Make sure the edges of the skillet are greased with butter. Pour batter over rhubarb in the cast iron skillet and place in a preheated oven, middle rack for 30-45 minutes.
- While baking, make sure to have ready what you plan to flip the cake onto. 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, continue baking longer, and check again every 5-7 minutes. Pull from the oven, let sit 5 minutes, run a sharp knife around the edges, then place a cake platter or cake stand over the skillet, and invert, gently tapping the bottom of the skillet so it releases.
- Serve with vanilla ice cream or whipped cream.
Notes
I use a 10-inch cast iron skillet for this recipe! I’ve tried it with a 9-inch spring form pan- and no leaks- but some readers have had issues with leaks. So 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: 346
- Sugar: 32.9 g
- Sodium: 331 mg
- Fat: 12 g
- Saturated Fat: 4.4 g
- Carbohydrates: 39 g
- Fiber: 2 g
- Protein: 6.8 g
- Cholesterol: 108.3 mg
Keywords: rhubarb cake, rhubarb cake recipe, gluten free rhubarb cake, upside down rhubarb cake, rhubarb recipes, rhubarb cake recipes, gluten free recipes
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!