If you’re living the keto lifestyle but still crave something sweet and seasonal, this Keto Rhubarb Cake is a must-try. With its moist texture, tangy-sweet flavor, and low-carb ingredients, this cake proves you can have your dessert, and stay in ketosis too.
Rhubarb, often overlooked, is a keto-friendly vegetable that shines in desserts thanks to its tart, fruity flavor. It’s naturally low in carbs and high in fiber, making it a perfect ingredient for low-sugar baking. When paired with almond flour, eggs, butter, and a keto-approved sweetener like erythritol or monk fruit, rhubarb transforms into a soft, luscious cake that’s just sweet enough to satisfy your cravings.
What makes this cake special is its balance of richness and brightness. The almond flour gives it a nutty, buttery base, while the rhubarb brings a punch of flavor and moisture. A touch of vanilla or lemon zest enhances the overall aroma, making each bite feel indulgent yet refreshing.
This keto rhubarb cake is incredibly versatile, you can bake it in a loaf pan, a round cake tin, or even as muffins for individual servings. It’s a fantastic option for spring and summer gatherings, whether you’re hosting brunch, celebrating a special occasion, or just treating yourself on a sunny afternoon. Top it with a dollop of sugar-free whipped cream or a drizzle of low-carb glaze for a little extra flair.
Best of all, this recipe is quick to make and stores well in the fridge, making it perfect for meal-prepping dessert for the week. With just a few simple ingredients and minimal effort, you can enjoy a guilt-free, gluten-free rhubarb cake, and completely keto treat that even non-keto friends and family will love.
So, if you’re looking to celebrate rhubarb season the low-carb way, this Keto Rhubarb Cake is the perfect blend of comfort and freshness.
Ingredients
- 1 cup almond flour
- 1/2 cup erythritol or preferred keto-friendly sweetener
- 1/2 teaspoon baking powder
- 1/4 teaspoon salt
- 3 eggs large
- 1/4 cup butter melted
- 1 teaspoon vanilla extract
- 1 cup rhubarb chopped
Instructions
- Preheat the oven to 350°F (175°C). Grease a cake pan or line it with parchment paper.
- In a bowl, mix together the almond flour, erythritol, baking powder, and salt.
- In another bowl, beat the eggs, then add melted butter and vanilla extract, mixing until well combined.
- Combine the wet and dry ingredients, mixing until fully incorporated.
- Fold in the chopped rhubarb gently.
- Pour the batter into the prepared cake pan and smooth the top with a spatula.
- Bake for 40 minutes or until a toothpick inserted into the center comes out clean.
- Allow the cake to cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.
Nutrition
Why is rhubarb so tart? I didn’t like the taste much in this. My family loved it though.
I thought it was supposed to be sweet, not tart! Are you sure about the recipe? 🤔
Rhubarb is supposed to be tart! It’s kinda what makes it unique. Maybe just add more sweetener next time?
Tastes good but really needs more rhubarb. I added some blueberries too!
Simple and sweet, just right for my diet! Great to use almond flour!
Good recipe if you like keto stuff. I found it a bit dry, maybe I missed something?
This cake was amazing! So moist and flavorful! I can’t believe it’s keto!
I’m so glad you liked it! It’s a game changer for keto desserts! 😊
I dunno, keto cake? Sounds weird to me. Is that even possible? 🤔
Followed this cake thing-it’s great! Can’t find rhubarb here, but still tryin!
Sounds delicious! You could try using strawberries or another fruit if rhubarb isn’t available. Good luck!
I’m skeptical about keto recipes. This one seemed too simple. Hope it’s not a flop.
I’m skeptical about using erythritol… I’ve tried keto desserts before, and they usually don’t taste good. But this one was surprisingly good!
This cake turned out amazing! It was moist and had just the right amount of sweetness. Can’t believe it’s keto! Will make again.
Who even likes rhubarb? 🤷♂️ I’d rather have chocolate. But for what it is, this cake is pretty decent.
5 stars!! Super easy recipe and the kids loved it! They had no idea it was keto. 😅
Keto and cake? Sounds like a lie! 😂 But I love rhubarb, so I tried it. Actually not bad for being healthy?
I don’t get what the fuss is. Cake should just be cake, not some healthy version. This was just weird.
I actually think it’s really cool people are trying to make healthier options. Cake can be yummy and still good for you! Give it a shot! 🙂
Healthy cake? Sounds like an oxymoron. Just stick to real cake, please.
So good! I added nuts to mine! Will make for family gatherings for sure. Almond flour is a game changer!
It didn’t bake well enough for me, took longer than stated, and got a bit dry. Not going to make it again.
I accidently used regular sugar instead of erythritol, but it still turned out fine! The rhubarb gives it a nice tartness.
Yum! I loved it! Didn’t have erythritol, so I used regular sugar. I guess that’s not keto, but it was delish!
This cake is amazing! I made it for my keto friends and they loved it. Will definitely make again!
I don’t know, man. Rhubarb? Really? I thought this was gonna be like a regular cake. Not a fan.
Not sure about rhubarb either. Isn’t it poisonous? Why are we eating this in cake? Just stick to chocolate cake!
Rhubarb is like super tasty, you just gotta try it! It’s not like regular cake, but it’s good in its own way. Give it a chance!
This keto rhubarb cake is simply amazing! I never thought keto could taste this good! 😍
Easy recipe! I love that it’s keto too! My kids even liked it, and they usually hate anything healthy!
That’s awesome! Glad your kids liked it! Keto can be tough to please everyone but sounds like you nailed it!
Just made this and it turned out super dry. Did I miss something? Anyone else have this issue?
I had the same issue! I think the rhubarb makes it too wet sometimes and you might need to adjust the almond flour amount. Try less baking time too!
I love rhubarb but I was nervous about almond flour. Turned out moist and not “eggy” at all. I used monk fruit instead of erythritol and it still worked.
Rhubarb? Never heard of it. Can I use apples instead? What’s the difference?
I dunno, the texture was kinda weird. Maybe too much almond flour? It wasn’t what I expected.
Just sounds like you did something wrong. I made this cake and it was perfect! Did you follow the steps?
I had the same issue with the almond flour! Maybe try adjusting the ratios next time? More butter could help.
Keto rhubarb cake?? Who eats this stuff? Not for me, sorry.
This looks fake to me—keto cake without flour can’t really be cake. But… I guess it was edible? Texture was weird.
Not gonna lie, my texture was weird too… kinda dense and a little gritty. I think I underbaked it because my toothpick came out “kinda clean” lol. Still ate it tho. Flavor was okay, just wouldn’t call it real cake.
I get why it sounds fake, but keto cakes *can* be cake—almond flour is basically the “flour” swap. I made this and it was edible, just not the same crumb as regular flour cake. Rhubarb gave it a nice tang.
Made this last night—so good! The rhubarb tartness totally balances the sweetener. Mine took closer to 42 minutes but still came out perfect.
Wow, I didn’t even know I could bake Keto! This was super easy and tasty. A must-try!
Keto? I’m still trying to figure out what that even is! But this cake looks good, might give it a try!
Mine was kinda dense in the middle even though the toothpick came out clean. I wonder if 40 minutes is too long/short depending on the pan size?
Not bad, but mine came out a little dense. I think I overmixed after adding the rhubarb (or my eggs were smaller). Next time I’ll be more gentle.
Not gonna lie, keto sweeteners always leave an aftertaste for me. I might reduce the sweetener next time and use more vanilla or a real sugar-free glaze.
Totally get that—erythritol can be kinda “cooling” and leave a weird aftertaste. Reducing it and leaning more on vanilla sounds like a good fix. You could also try monk fruit (some brands are smoother) or add a pinch of salt to balance flavors.
I used salted butter instead of unsalted and added a pinch less salt. Flavor was great, and the crust browned nicely. Would definitely bake again for brunch.
Do you really cool it 10 min in the pan? I waited like 30 and it was harder to get out, lol. Otherwise super easy and the rhubarb flavor was strong.
I followed the recipe but my eggs were cold and the batter got kinda clumpy. I whisked longer and it came together. Baking time was about right after that.
Glad it came together! Cold eggs can definitely make the fat seize up a bit, especially when you add melted butter. Next time maybe let the eggs sit out 10–15 min or warm the melted butter slightly.
Huh, my batter never does that… but maybe your rhubarb was too wet? Also I feel like 40 min is a little long for keto cakes—mine usually needs less. Still, good job tweaking it.
Not gonna lie, I’m skeptical of keto cakes. But this one didn’t taste “diet.” The rhubarb makes it bright. Would bake again.
I’m not sure about the 1 cup rhubarb amount. Mine was really watery, so the batter looked looser than expected. Maybe I should’ve patted it dry?
The toothpick test worked, but the middle was slightly underdone at 40 minutes. I gave it 8 more and it fixed it. Otherwise solid.
Wow. Easy and tastes like spring. 10/10. (Also I didn’t fold gently and it still turned out fine 😅)
Really? I’ve made keto cakes that get kinda dense if you don’t fold carefully… what size pan did you use? Mine took closer to 45 min.
Love hearing that! The springy vibe makes sense with rhubarb—also I totally respect the “didn’t fold gently” honesty 😂
Made this for dessert last night—surprisingly good for a keto cake. The rhubarb tartness balances the sweetness really well. Mine baked closer to 38 minutes, but the toothpick method worked.
Not sure I got the bake time right. Mine was still a bit wet in the center after 40 minutes, so I ended up adding ~10 more. Tasted fine though.
Good to know! I was worried about the rhubarb making it wetter. My toothpick usually needs a little extra time too—maybe 45-50 mins is more realistic than “clean” at exactly 40.
Mine never came out wet… or maybe my oven runs cold? I cooked like 30 mins and it was done lol. Also I used honey (oops) so maybe that changed it. 10 more minutes sounds reasonable tho.
This turned out way better than I expected—nice and moist for a keto cake. The rhubarb actually gives it a bright tang instead of just tasting “diet.”
Good flavor, but mine browned a bit too fast around 35 minutes. I’d start checking earlier next time and maybe tent with foil.
Not bad at all for keto. I used monk fruit instead of erythritol and it tasted a little “cooling” at first, but after a day it improved.
I used a different keto sweetener (monk fruit) and it still worked, but I think I’d reduce it a bit—the flavor was slightly bitter. Otherwise great texture.
Rhubarb in a cake is genius. I’m not keto but I tried it and it tasted like a fancy dessert. Will make again for sure.
Just tried this and I think I messed something up. The cake was super dense and not sweet enough. Help?
Erythritol leave that cooling taste for me. Cake was fine, but I’d try a different sweetener next time. Also, vanilla could be a little stronger.
Totally get it—erythritol can have that weird cooling vibe. I’ve swapped it for monk fruit (or half/half with a regular keto sweetener) and it’s way smoother. Good call on boosting the vanilla too; 2 tsp might do it.
Huh, I like erythritol 😅 The cake is kinda bland though, so I’d agree about vanilla. Next time add more vanilla and maybe a pinch of cinnamon. Also is rhubarb really 1 cup? Mine made it too tart.
OMG this is a game changer! So fluffy and delicious. Rhubarb is the best! 😍
I know right?! Rhubarb just elevates everything! 😋
Really loved how the rhubarb tartness balances the sweetener. Came out moist and not “eggy” at all. Will make again!
Sweetener note: my erythritol left a slight cooling aftertaste. Next time I’ll try a different keto sweetener or reduce it a bit.
Keto people always say “clean toothpick” like it’s easy 😂. I tested twice and still got crumbs. Tasted delicious regardless, but it’s more like a dense cake than fluffy.
I’m skeptical about almond flour cakes getting the texture right, but this one wasn’t dry. Still, I think 1/4 tsp salt might be a bit much? Idk.
So simple! 😅
Followed the steps exactly—350°F for 40 min was perfect for my oven. I used erythritol and it tasted great, not overly bitter.
Nice! I’m glad the 350°F/40 min worked for you—mine always runs a little hot, so I was worried. Did you find the rhubarb got nicely tender or still a bit tangy/crunchy?
Rhubarb is underrated. This cake tastes like a fancy brunch thing. The almond flour texture is a little crumbly, but honestly that’s kinda expected.
I think the baking powder might be too much? Mine didn’t rise much, and it was a little dense. Maybe my eggs were smaller?
Pretty good, but I think I used too much rhubarb (I packed it in). Still tasted great though—just a bit gummy in the middle. Next time I’ll weigh it or chop smaller pieces.
Totally makes sense—packed rhubarb could definitely add extra moisture and make the middle gummy. Weighing it next time is a great call. I usually chop fairly small too so it bakes through evenly.
I’m not a baker person, but this was pretty straightforward. The batter was thick like shortbread dough though, so I had to smooth it gently.
Mine came out kinda dense too, and I think I overmixed it. Also I used brown sugar instead of erythritol once… don’t do that 😅 but still tasty!
Honestly that sounds about right—keto batters with almond flour can be way thicker than wheat-based ones. Smoothing gently is the move.
Erythritol leaves a cooling aftertaste for me, so I’m not a fan. The cake itself was good, but I could taste that sweetener vibe. Might try allulose next time.