Make the most of rhubarb season with these Keto Strawberry Rhubarb Crumb Bars. A tender, crumbly low carb crust with a sweet fruit filling, they make the perfect spring dessert!
Have I ever mentioned how much I love strawberry rhubarb? Maybe yes, maybe no? Well let me tell you again in no uncertain terms. I LOVE STRAWBERRY RHUBARB!
Every year, I make big batches of sugar-free strawberry rhubarb sauce. We put it in yogurt, over my keto ice cream, and sometimes I just eat it with a spoon. It’s also fabulous as a topper for keto waffles.
And sometimes I am inspired to bake with it too. And these tender, deliciously crumbly Keto Strawberry Rhubarb Bars are the perfect way to showcase one of my favorite flavors.
Why you must try this recipe
This is actually an update to a very, VERY old recipe of mine that I published over 12 years ago. My keto baking skills have come a long way since then. And keto baking products have come a long way since then too!
When I came upon some fresh organic rhubarb at one of my grocery stores, the inspiration to re-make them, and make them BETTER, hit me. And I am delighted to say that I rose to the challenge.
This time around, I used the crust from my Keto Salted Caramel Butter Bars, which is both sturdy and tender. I also thickened the strawberry rhubarb filling so that it wouldn’t make the crust too soggy.
The resulting bars were everything I wanted them to be. Apparently my neighbors, to whom I gifted a few of the bars, felt the same way!
These delicious keto crumb bars are easy to make and have only 3g net carbs per serving.
Ingredients needed
- Strawberries: Fresh strawberries will give you the best filling, but you can use frozen if that’s more convenient. Just make sure to thaw and drain the berries to remove excess moisture.
- Rhubarb: Fresh or frozen rhubarb is fine here.
- Almond flour: You really do need to use a good finely ground almond flour for this recipe. No other nut meal or flour will give you the same shortbread like consistency.
- Coconut flour: A little coconut flour in the crust mixture helps offset the moisture in the almond flour.
- Sweetener: I recommend an erythritol-based sweetener for the crust, to allow it to firm up properly. For the filling, you should use allulose for a nice, syrupy sweet fruit mixture. If you can’t use allulose, try powdered sweetener.
- Glucomannan: Most cobbler bars take cornstarch to help thicken the filling, but a little glucomannan or xanthan gum does an admirable job for this keto version.
- Butter: This recipe will turn out best with real butter. But you could use some butter alternatives if you need to be dairy-free.
- Pantry staples: Vanilla extract and salt.
Step-by-step directions
1. Prepare the crust mixture: In a large bowl, whisk together the almond flour, sweetener, coconut flour, and salt. Stir in the melted butter and vanilla until the dough begins to clump together.
2. Bake the bottom crust: Press about two thirds of the dough into a greased 8×8 inch baking pan and bake at 350ºF for 10 minutes. Remove from the oven and let cool 10 minutes to firm up.
3. Prepare the filling: Add the rhubarb, strawberries, allulose, and water to a pan over medium low heat and bring to a simmer. Allow to cook until the fruit softens and begins to release liquid, about 5 to 8 minutes.
4. Thicken the filling: Remove from heat and add the glucomannan, whisking briskly to combine. Allow to cool and thicken 10 minutes.
5. Assemble the bars: Spread the filling evenly over the cooled crust and sprinkle the remaining crust mixture overtop. Bake another 20 to 25 minutes, or until the crust is light golden brown.
6. Refrigerate: Remove and let cool completely, then refrigerated one hour to firm up before cutting into bars.
Expert tips
If you can, use fruit that has a deep red color, as it makes the filling more pink and looks more attractive. It can be hit or miss with rhubarb, though! Even a deep red exterior can have a light green center. It doesn’t affect the flavor, it’s just about aesthetics.
Because strawberries and rhubarb both contain a fair amount of liquid, it’s important to thicken the filing before spreading it on the bars. That way, the bottom crust stays more crisp. You can use glucomannan or xanthan gum. You can even try using a little gelatin.
Sweetener Options
If you want your crust to be crisp, you really need to use an erythritol based sweetener that contains no allulose whatsoever. I used a version of Swerve Sweetener that is only erythritol and monk fruit.
The filling works best with allulose, as it makes it more syrupy and thick. But you can use any sweetener here, since you will be using some thickener as well.
Frequently Asked Questions
Fresh rhubarb contains very few carbs per serving and is an excellent addition to your keto diet. Diced rhubarbs stalks have only 6g of carbs and 2g of fiber per cup. And it’s delicious in low carb desserts like these crumble bars!
Try using sunflower seed flour or another seed meal for the crust. Do be forewarned that it will have a different color and slightly different flavor.
This keto strawberry rhubarb bar recipe has 5.4g of carbs and 2.4g of fiber per serving. That comes to 3g net carbs per bar.
More delicious keto rhubarb recipes
Keto Strawberry Rhubarb Bars
Equipment
Ingredients
Crust
- 2 cups almond flour
- ½ cup granular sweetener
- 2 tablespoons coconut flour
- ¼ teaspoon salt
- 6 tablespoons butter melted
- ½ teaspoon vanilla extract
Filling
- 2 ½ cups chopped rhubarb
- 1 ¼ cups chopped strawberries
- 1 tablespoon water
- ⅓ cup allulose
- ½ teaspoon glucomannan
Instructions
Crust
- Preheat the oven to 350ºF and grease a 8×8 inch baking pan well.
- In a large bowl, whisk together the almond flour, sweetener, coconut flour, and salt. Stir in the melted butter and vanilla until the dough begins to clump together.
- Press about two thirds of the dough into the prepared baking pan and bake 10 minutes. Remove from the oven and let cool 10 minutes to firm up.
Filling
- While the crust is baking, prepare the filling. Add the rhubarb, strawberries, sweetener, and water to a pan over medium low heat and bring to a simmer. Allow to cook until the fruit softens and begins to release liquid, about 5 to 8 minutes.
- Remove from heat and add the glucomannan, whisking briskly to combine. Allow to cool and thicken 10 minutes.
- Spread the filling evenly over the cooled crust and sprinkle the remaining crust mixture overtop. Bake another 20 to 25 minutes, or until the crust is light golden brown.
- Remove and let cool completely, then refrigerated one hour to firm up before cutting into bars.
Alice O. says
The first time I made these exactly by the recipe and they were really good. The second time I made them I used cherries, strawberries, and blueberries. I put crushed pecans in the crust and keto dark chocolate chips on top of the filling. I just got them out of the oven and they smell good! I can’t wait to try them when they’re cooled.
Caroline Nielson says
I made this yesterday. These squares were so easy to make and were absolutely delicious!! Made it right to the recipe and they turned out lovely. The top was a little crumbly, but I’ve left them in the fridge overnight and I think that sorted it 🙂
Rhubarb has always been a favourite of mine and I always have some ready to go in the freezer. Thank you 🙂
Gabi says
Have you made Rhubarb cookies?
Carolyn says
I have not… but I like the idea!
Virginia says
Wildly delicious! (I used raspberries in lieu of strawberries.)
Carolyn says
Great to hear!
Wendy White says
I have made this before the update and this looks even better! Going to try a swap for vegan butter so that my niece can enjoy them as well at our mother’s day brunch!
Carolyn says
This one is much better. The old one was very old! 🙂
Catherine says
Can you use non-flavored psyllium fiber in place of glucomannan? Or is there another alternative? It seems like I keep adding these different items and then only use them once in a while. LOL, I just thought I would ask.
Carolyn says
I think you will to experiment a bit. I haven’t tried psyllium in this.
Lovisa says
could you use stevia or maybe coconut sugar in place of allulose?
Carolyn says
Please read the Expert Tips section as I already addressed this question. 🙂
Carolyn says
I guess you will need to experiment!
Tyronna Gutelius says
I love this time of year when you can get fresh strawberries and rhubarb