This sweet keto rhubarb tart with a crumble topping is the perfect spring dessert. Easy, delicious, and totally sugar-free.
Have I ever mentioned that I am a rhubarb fanatic? I am crazy about that stalky low carb vegetable and I’m always delighted to see its arrival in my local stores.
Yes, rhubarb is indeed a vegetable, although we tend to treat it as a fruit in baking and cooking. It’s a classic for desserts, like my Keto Rhubarb Crisp.
Rhubarb is often paired with strawberries, such as in my Strawberry Rhubarb Dump Cake. But it doesn’t have to be. It’s also amazingly delicious as the star of the show.
And in this delicious keto crumble tart, rhubarb definitely plays the starring role!
Is rhubarb poisonous?
There is a common misconception that raw rhubarb is toxic. In fact, I myself used to think so, because my older brother got quite sick on rhubarb when we were young.
However, the rhubarb stalk is edible raw or cooked. The rhubarb leaves, on the other hand, contain high amounts of oxalic acid and can be toxic.
Most grocery stores and farmers markets sell the stalks only, so there’s little risk of toxicity. If you grow your own, do be careful to cut off all the leaves before cooking.
Keto Rhubarb Tart Inspiration
The main inspiration for this recipe was the rhubarb itself. I’ve been dreaming of rhubarb desserts since February and grabbed a few stalks the moment they hit the shelves.
But I am always saving recipe ideas on Pinterest and I recently spotted this gorgeous tart from The View from Great Island. It was picture perfect!
And with the recent success of my Keto Pumpkin Crumb Cake, I knew I could mimic that delicious crumble topping with my keto friendly ingredients.
How to make Keto Rhubarb Tart
This is an easy keto recipe that results in a delightful dessert. Here are my best tips for getting it right.
The pan
I recommend a metal tart pan with a removable bottom, like this one. It helps the crust crisp up properly and it’s easier to get the tart out of the pan.
If you don’t own such a pan, you can make this recipe as crumble bars in a metal 8-inch square pan. You could also use a springform cheesecake pan.
Be sure to grease the pan properly!
The crust
This is an almond flour shortbread crust, so it doesn’t contain any eggs. It’s designed to have a crumbly consistency. The coconut flour is important for getting that crumbliness, particularly in the top crust.
Press the bottom crust firmly into the pan so it holds together a little better. Then par-bake it for about 18 minutes. It won’t seem fully cooked at this point but it will firm up as it cools.
Just be sure to let it cool properly!
The sweeteners
I know many people want to use the same sweetener for everything and hate when a recipe calls for more than one. But keto sweeteners do not behave like sugar in baking. You need to understand their different properties to get the right results.
The crust takes Swerve because erythritol is the only sweetener that properly crisps up in crusts and cookies. You can just do granulated Swerve if you want.
The filling takes allulose because it helps get the right syrupy consistency without recrystallization. You could use powdered Swerve here but just know that it may become a bit gritty as the tart cools.
Thickening the filling
Like many stalky vegetables, rhubarb releases a lot of liquid during cooking. To avoid making the crust soggy, I recommend pre-cooking it with a little liquid, and then thickening the mixture.
For recipes like this, I like glucomannan to thicken the filling. But xanthan gum or even a little collagen can work too.
Can you make keto rhubarb tart in advance?
This delicious crumble tart is best served fresh. The rhubarb filling does begin to soften the bottom crust after the first day.
That’s not to say it’s not absolutely delicious anyway! I gave a portion to my neighbour and he ate it warmed up for breakfast!
Do store any leftovers in the refrigerator.
More amazing keto tart recipes
- Cannoli Tart
- Keto Butter Tarts
- Tomato Goat Cheese Tart
- Chocolate Macadamia Tartlets
- Keto Cranberry Brie Bites
- Lemon Blackberry Tart
Rhubarb Crumble Tart
Ingredients
Crust and Topping
- 2 cups almond flour
- 1/3 cup Swerve Brown
- 1/3 cup Swerve Granular
- 2 tbsp coconut flour
- 1/2 tsp cinnamon
- 1/4 tsp salt
- 1/2 cup butter, melted
- 1/4 cup chopped pecans or walnuts, (optional)
Rhubarb Filling
- 3 cups chopped rhubarb
- 2 tbsp water
- 1/3 cup allulose , (or BochaSweet)
- 1/4 tsp glucomannan, (or xanthan gum)
Instructions
Crust
- Preheat the oven to 325F and grease a 9-inch metal tart pan with a removeable bottom.
- In a large bowl, whisk together the almond flour, sweeteners, coconut flour, cinnamon, and salt, breaking up any clumps with the back of a fork.
- Stir in the butter until well combined. Press about 2/3 of the dough firmly and evenly into the bottom of the prepared pan. No need to go up the sides.
- Bake 15 to 20 minutes, until just golden brown around the edges. Then remove and let cool at least 15 minutes to firm up.
Filling
- While the bottom crust is baking, prepare the rhubarb filling.
- In a medium saucepan over medium heat, combine the rhubarb, water, and allulose. Bring to a simmer and cook 5 minutes, until softened and the rhubarb releases some juices.
- Stir in the glucomannan and let cool to room temperature.
To assemble
- Once the filling is cool, spread evenly over the cooled bottom crust.
- Add the chopped nuts to the remaining crust mixture. Sprinkle the crust mixture over the filling, pressing lightly to adhere.
- Bake another 20 minutes, until the top crust is beginning to brown. Remove and let cool completly in the pan.
- Use a small sharp knife to gently loosen the side of the pan and remove the sides before cutting into slices.
Nutrition
Nutritional Disclaimer
Please note that I am not a medical or nutritional professional. I am simply recounting and sharing my own experiences on this blog. Nothing I express here should be taken as medical advice and you should consult with your doctor before starting any diet or exercise program. I provide nutritional information for my recipes simply as a courtesy to my readers. It is calculated using MacGourmet software and I remove erythritol from the final carb count and net carb count, as it does not affect my own blood glucose levels. I do my best to be as accurate as possible but you should independently calculate nutritional information on your own before relying on them. I expressly disclaim any and all liability of any kind with respect to any act or omission wholly or in part in reliance on anything contained in this website.
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This is by far THE best Keto dessert recipe I’ve ever made and it’s super easy too! I did use 5 cups of rhubarb and then adjusted the rest of the filling recipe to match and to me it was perfect. I also added some nutmeg and I used Xanthan Gum because I don’t have glucomannan.
It was SO delicious…. I can’t wait until tomorrow to have another piece!!
Glad you enjoyed it!
Is it possible to use berries in place of the rubarb? I’m a very good cook, but most things I bake turn out awful! However, this looks like something I might be able to manage and would love to make it with berries.
Another keeper! Carolyn, you are the best! I do not even look elsewhere for low carb recipes, yours are perfect, easy, fail safe and soooo yummy!
Thanks so much!
I omitted the crumble on top, then inverted the tart after baking and cooling. The crust stayed crispy for days!
I was looking for a crumble recipe and decided this would work for chayote squash and zucchini filling. I had them and needed to use them, didn’t have any rhubarb. I used two each of the squashes with lots of cinnamon to taste like apple pie. I followed the recipe otherwise. My DIL and her mother loved it. Husband just had some and thought it was apples. Success! Thank you for making me look good.
This was truly amazing, but it is best to eat the day you make, texture gets gooey/crumbly the next day. I’m going to make these in individual tart pans, prepare and freeze ingredients separately, then I can bake whenever I want one! Thanks so much for this recipe.
Carolyn I made your Rhubarb Crumble Tart today, and it is delicious. I’ve made many of your recipes and enjoy when I check my emails and see you’ve done it again…????. Thanks for all your work experimenting to give us so many tasty treats. Yum ????
Thank you so much for sharing your expertise! I just attempted rhubarb syrup with a sweetener other than allulose and sure enough – it crystalized! Headed straight to your blog for assistance/advice. Bless you!
Yes, I can see that would be an issue!
My daughter and I love this recipe! Such a hit here and very yummy! Making this recipe again soon!
That crumble is the best & I love the rhubarb flavor!! So happy this is keto-friendly!
I used an 8-inch square pan, and the recipe turned out great. I love the tartness of rhubarb.
This was outstanding! I’ve been doing keto for four years, and this is the first time I’ve tried making anything with rhubarb. It was so great to have a real fruit tart again. Buttery, sweet, tart – just perfect. A little whipped cream on top was good too. Not at all difficult to make either.
I am so excited to make this when my rhubarb is ready to harvest! It’s tricky to find keto recipes that don’t require eggs. And I love that this is JUST rhubarb, no strawberry or other flavors. Hugs to you!
Glad this one works for you. My rhubarb crisp recipe is also egg free so check that one out!
Before I make this recipe is there any chance that you can give me similar alternatives for your American sweeteners (Bocha Sweet & Allulose) as we can’t seem to purchase them on Amazon.ca. LOVE all your recipes, Jill
Stay safe. 🙂
Someone just told me about a place in Canada, (online store) that is selling both of them, I believe. Low carb canada or similar site. You can try xylitol but it does tend to spike people a bit more.
I’ve sourced allulose at GTA Nutrition – perhaps that’s an option.
I’m making this today! I love rhubarb. Under assemble instructions #2, are you missing the word nuts?
Thanks for continuing to create and share wonderful keto recipes.
Very possibly! It’s hard to edit your own work and see the mistakes… your brain automatically fills in the blanks. I will fix it.
I there some other ingredient that can replace allulose, because I cannot buy allulose over here in the Netherlands. Also I cannot order it in the United States or if I can order it is very transorting fee
Please read the blog post, as I tell you what you can use. Don’t spend the extra money but you may have to make friends with a little recrystallization.
Sorry, my bad.
I did not read that. I can use stevia I read.