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.
Mark Nepo
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 soda 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: 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
Such a hit! I served it for a girls luncheon. I was so happy with the results. My only complaint was although I followed the UTube to line my spring form pan it still leaked. Next time I would not tear away the paper & certainly stand the pan on a lined oven tray to catch the juices. I will certainly be making it again.
Love this recipe . . . I had to replace some of the almond flour (I used meal) with hazelnut, as I ran out . . . but it was amazing! Thank you for the recipe.
Oh goodie! Im so glad it worked for you!!
Made this recipe last week and loved it so much I’m making it again with the last of our rhubarb. First time I used a springform pan – it only leaked a small amount. This time I decreased the sugar in the cake portion a bit and am baking it in a heavy duty Dutch oven (don’t have any cast iron). Hope it comes out! Love the lemon flavor that really sings in this recipe!
Do you have any ideas to make this nut free? I’m have an almond allergy.
This recipe is now my go-to dessert in the spring when the rhubard is fresh. The whole family loves it, gluten-free or not. I had never been much of a fan of rhubarb until this recipe, and now i can’t get enough. Sweet, but not too sweet, and tangy. Thank you!
This cake is amazing and will be added to my tried and true crowd-pleasing recipes. And I will share it with my friends. When I flipped the cast iron pan some of the rhubarb stuck in the pan but I just scraped it out and spread it on top of the cake and you would never know the difference.
Oh Great to hear! It’s looking like the cast iron skillet method is turning out better than the spring form pan….thanks Jennifer!
H!! I followed this to the letter, except I used, as you suggested, a spring form pan lining the bottom with buttered parchment. I now have caramel dripping all over my oven. Haven’t pulled cake out yet to see if it is edible. What did I do wrong?
Hi Marianne, Im so sorry about the mess- so frustrating! I updated the recipe and added more directions for lining a spring form pan. A couple things may have have happened- in the recipe I added a link for a video on a good way to line a spring form pan that helps prevent leakages. Its also pretty common that people will put the bottom of the pan in upside down.Some pans just don’t have the best seal. If unsure, good to wrap in foil or place on a sheet pan in the oven- in any case I’m sorry it happened.
I got a sheet pan in there pretty quickly and it caught a lot of it. This was a new pan I bought, specifically because it seals better. I have tried wrapping in foil before but it still seep into the foil where it can burn (or in the case of a Cunard, provide an interesting exterior omelet collar LOL. But I like what that video shows – will try that next, thank you. PS Cake looks excellent – hubby is whittling away at it. I better grab some for my 90 year old mom before he inhales the whole thing. I will taste this afternoon (don’t eat cake in the evening).
Oh good, I really hate oven messes, glad it wasn’t too horrible. Ok, well thanks for the feedback hope it tastes good.
The comments from Mister “I know how to line a spring-form pan” Do. Not Always. Work. Third time making this, still getting sticky rhubarb juiced.caramel everywhere.
Marianne- out of simplicity, I am updating the recipe to encourage using a cast iron skillet. Several readers are having problems with leaking and I hate the thought of having to clean up a huge mess. I’m so sorry it happened to you, so unfortunate.
I made this last night it came out great. My husband and I enjoyed it so much we had a piece with coffee this morning. I used maple sugar instead of white sugar and baked it in a cast iron pan. I will definitely make it again, since my neighbors garden is overflowing with rhubarb.
Did the springform pan method and the rhubarb juices leaked out and caused quite a bit of commotion in my house when it burned on the bottom of my oven. If using a springform pan, scoop the rhubarb out without all the juice. The rhubarb and cake was still tangy and moist? You could use the juice later as a drizzle over the ice cream if you reduce it or thicken it. That’s what I did
Hi Bob, thanks for feedback. Did you line your springform with parchment? It helps the juices stay in. Here’s a video on how to line to help prevent leakages How to line a spring form pan
Made it for a potluck and didn’t have any left to bring home. I used brown sugar instead of white and loved the extra caramel hint. Thanks for the great recipe. Will definitely keep this one as a favorite.
Awesome Debb!!
My 10 year old and his two friends made this cake to take to a birthday party as a gluten free offering. It was easy to make (kids whipped egg whites by hand) and was a hit at the party with adults and kids alike. It was served just as is. The kitchen ended up a bit of a mess but they were able to make a desert that looked and tasted wonderful with minimal supervision. The cardamon really set it off and it was not too sweet. Almond flour is a pretty expensive ingredient where we live, so we will try local hazelnut meal next time as there’s still plenty of rhubarb around.
I think my son’s cake looked even better than the one in the picture.
Do you think it could also work with quinces?
Thanks for the recipe.
Ahhh….. love love love that your 10 year old son made this! that is awesome! I think it would be great with quinces! 😉
Hi, thanks so much for this recipe! Rhubarb is so delicious. I love these flavors and the texture, but I am wondering if I could cut back on the sugar somewhere? I like the candied texture of the rhubarb but the cake as a whole is too sweet for me. If I cut back on sugar in the rhubarb, would the top texture be too loose or wet? I always ruin my rhubarb dishes’ texture by cutting back on the sugar (to preserve the delicious tangy-ness) and end up with a soggy result. Will the cake part turn out if I cut back on the sugar? I really want to make this again!
I have never cut back on the sugar, so I don’t know the answer to this honestly. If you do try it will you let us know how it turned out?
Soo Yummy, A real hit in this household! Thanks so much. 11/10
thanks Deb and great to hear!!!
Hi,
I am wondering if I could use regular flour instead of the almond meal. We have nut allergies but this cake looks so delicious I’d really like to give it a try 🙂
Thanks for always sharing your delicious recipes. We are a big fans of your cooking!
Cheers,
Sonja
You know…I haven’t tried it with regular flour so I can’t be sure. It seems like it should work, butI honestly don’t know.
Hi, I just made this – and it is really good. I’ve been gluten free for about 3 1/2 months and haven’t had too many successes with GF breads/treats, but this is great! My husband who doesn’t eat GF really said it was really delicious and just went for seconds! I worried that when I flipped it over out of the pan that the juicy rhubarb would make the cake soggy – and it did a bit, but not too bad at all. I served it with a little vanilla ice cream.
I would love to make just an almond cake too – I love the flavor of this (first time trying almond flour) – have you ever tried just making the cake in the skillet? I wonder if it would come out easy enough…?
Anyway, thank you for the recipe. I like to come back and actually give my results to help others – sometimes there isn’t enough feedback on what others actually experienced.
Hi Ruthie,
Thanks so much for your feedback…it really does help others to know that a recipe is successful.
All the best to you on your journey and thanks for visiting the blog.
Sylvia
This cake looks wonderful! I am wondering about the 2 tsp vanilla. In the ingredients list it says “divided”, but in Step 1 you say to use all the vanilla with the rhubarb and you don’t mention using vanilla later on in the batter. Which part is correct?
Hi Millie,
It all goes in the rhubarb! Thanks- I fixed the recipe!
I had to bake this for 1hr to get right consistency. And I used 1/4 cup of stevia instead of sugar in the rhubarb portion. Great idea whipping the eggs so much, its worth it!
Just made this – very tasty! Mine was quite moist (almost soggy) but I’m not that talented when it comes to baking. Still, I’m keeping the recipe and using it every rhubarb season! Yuuummm
Shoot. It probably just needed to be baked a little longer. Do you do the toothpick test?
This was delicious! and beautiful, I might add. I think whipping the egg-whites really made the difference.Thank you 🙂
Oh yum!! Sooo baking this one!!
I love rhubarb, I’m currently dedicating May on my blog to all things on this vegetable. This cake looks delicious, I love almond paired with rhubarb.
This sounds literally amazing, I adore almond cake so much and the tender sweetness of the almond must bring the rhubarb to life!
I have almond flour in the freezer, just need to find the rhubarb. This is beautiful.
Perfect! Give it a whirl.
I take my Rhubarb Pinterest board VERY seriously….and I couldn’t pin this fast enough! Beautiful recipe!
This cake is gorgeous! And I love the flavour 🙂
thanks Katrina!