This keto rhubarb cake offers three layers of gorgeousness: a moist yet light and fluffy vanilla crumb, a sugar free rhubarb filling and a delicious cinnamon streusel topping. It's a cake recipe the entire family will enjoy, whether they are on a low carb diet or not! Only 10 minutes prep.
Even though I have lived in London for more than half my life now, I'm not doing high tea in the afternoon. True to my German roots, I am more of a "Kaffee und Kuchen" person. Coffee and cake, that's what Germans do in the afternoon.
In my home town Hamburg, you'll get invited to a "Kaffeeklatsch", which loosely translates into "coffee gossip". Which is where this cake comes in! I have grown up with rhubarb cakes (we always grew rhubarb in the garden) and really wanted to make my own sugar free version.
This cake is one of my favourite keto rhubarb recipes. I love a good crisp or crumble, and I'm known for my keto rhubarb muffins. I'll post both soon. But now, let's get going with today's recipe!
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Ingredients
Here are the ingredients you'll need:
- Rhubarb
- Eggs - these should be large and room temperature
- Butter, cream cheese and almond milk
- Granulated sweetener - I used a golden erythritol monk fruit blend, but a granulated white sweetener will work just as well. This cake is gently sweet - add up to ⅔ cup sweetener if you prefer.
- Almond flour - I'm using what we over here in the UK call ground almonds. This is equivalent to regular almond flour in the US. If you're using super-fine almond flour, I would reduce the amount by 2 tbsp.
- Coconut flour - because it complements almond flour just so well in gluten free low carb recipes.
- Plus baking powder, vanilla extract, cinnamon for the streusel and optional almond extract for the cake batter.
Instructions
(This section contains step by step instructions and photos that show how to make this recipe. Find the recipe card with ingredient amounts and nutritional information at the bottom of the post.)
Prepare the rhubarb: If the stalks are thick and woody, peel and cut them into thinner slices, about a finger thick. Then chop into 3-5 cm long pieces and mix with the sweetener. Let the mix sit for 30 minutes to macerate.
This process draws out excess liquid and prevents the cake from becoming soggy. You'll end up with a fair amount of liquid in the bowl!
Sugar free cake batter: Now, beat the eggs until pale, fluffy and double in size. This should take about 2 minutes.
Add the sweetener, melted and cooled butter, cream cheese, almond milk vanilla extract and almond extract (if using). Continue beating for another 1 minute.
Mix the almond flour, coconut flour and baking powder in a separate bowl. Then add them to the wet ingredients and blend until you have a smooth batter.
It should look like this!
Cinnamon streusel: Next, mix the streusel. No separate pic for this, just mix all ingredients in a separate bowl using a fork (and try not to eat all of it straight away - it's super yum).
And now let's assemble this rather awesome keto rhubarb cake!
Fill the cake batter into the prepared springform. Arrange the rhubarb pieces in a single layer over it...
... and top everything off with the sugar free streusel mix.
Baking times
I baked my cake on the middle shelf for 63 minutes in total. I've given you a range of 60-65 minutes.
Check with a skewer or knife that the middle is baked and not wet, keeping in mind that the rhubarb will be soft and sticky.
Most importantly, check the cake after 35-40 minutes. If the streusel have browned sufficiently, loosely cover it with a piece of aluminium foil to prevent burning.
Baking in other cake pans
If you use a different sized baking pan be aware that the baking time will differ.
The first time around I baked this cake in a small 18 cm / 7 inch springform, which increased the oven time by 10 minutes.
A larger round or rectangular pan will need less time - probably only about 40-45 minutes. Basically, the flatter the cake is, the less oven time it needs.
Whichever pan you use, let the keto rhubarb cake cool completely before releasing it from the springform. Low carb cakes are fragile when hot and firm up as they cool.
To ensure it does not break or split, run a knife around the edges before you open the form.
Recipe variations
No coconut flour - To make this cake without coconut flour, replace it with 3x the amount of almond flour.
Dairy free - For a dairy free keto coffee cake, replace the butter with coconut oil and the cream cheese with coconut cream.
Using different fruits - This cake would work well with berries. Try using my Easy No-Cook Sugar Free Raspberry Jam as a filling! Or add a few strawberries for a keto strawberry rhubarb cake.
Serving suggestions
Sugar free icing - Want to go the extra mile? Top the crumbles with a vanilla flavoured sugar free drizzle! Simply mix 2 tablespoon almond milk with 4 tablespoon powdered sweetener and ½ teaspoon vanilla extract until you have a thick, but pourable consistency.
Fill into a ziploc bag, cut off a little corner and drizzle the icing over the cooled cake.
Alternatively, serve with a dollop of Sugar Free Keto Whipped Cream or a scoop of Sugar Free Low Carb Ice Cream.
Storage
Store in the fridge for up to 4 days or freeze for up to 3 months.
Related recipes
Tried this recipe? Give it a star rating below!
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Recipe
Keto Rhubarb Cake
from Sugar Free LondonerNote: The servings slider only changes the first amount in each line and not any subsequent amounts. Please make your own calculations where necessary. ***As an Amazon Associate I earn from qualifying purchases.
Equipment
- 20 cm / 8 inch springform pan
Ingredients
- 1 cup / 140g rhubarb diced
- ¼ cup / 50g granulated sweetener for macerating (soaking)
Cake
- 4 eggs large, room temperature
- ½ cup / 114g butter melted, then cooled
- ¼ cup / 60g cream cheese
- ¼ cup / 60ml almond milk
- ½ cup / 100g granulated sweetener use up to ⅔ cup if you like a sweeter cake
- 2 cup / 200g almond flour
- ¼ cup / 30g coconut flour
- 2 teaspoon baking powder
- 1 tablespoon vanilla extract
- 1 teaspoon almond extract optional
Streusel
- ½ cup / 50g almond flour
- 1 tablespoon coconut flour
- 2 tablespoon butter melted
- 1 ½ tablespoon granulated sweetener
- 1 teaspoon cinnamon
Instructions
Prepare Rhubarb
- Chop the rhubarb into circa 3-5 cm long, finger-thick pieces. Large rhubarb stalks may benefit from peeling first. Mix the chopped rhubarb with the sweetener. Let it sit for 30 minutes to macerate. This process draws out excess liquid and prevents the cake from becoming soggy.
Cake Batter
- Preheat the oven to 180 C / 350F and line the bottom of a 20 cm / 8 inch round springform with parchment paper. Grease the sides with butter.
- In a large bowl using an electric mixer or in a food processor, beat the room temperature eggs until pale, fluffy and double in size. About 2 minutes.
- Add the sweetener, melted and cooled butter, cream cheese, almond milk vanilla extract and almond extract (if using). Continue beating for another 1 minute.
- Mix the almond flour, coconut flour and baking powder in a separate bowl. Then add to the wet ingredients and blend until you have a smooth batter.
Streusel
- Mix all ingredients in a separate bowl using a fork.
Assembly
- Fill the cake batter into the springform. Arrange the rhubarb pieces in a single layer over it. Top off with the streusel mix.
- Bake in the preheated oven on the middle shelf for 60-65 minutes or until a skewer inserted comes out free of dough. Check after 35-40 minutes. If the top of the cake has browned sufficiently, loosely cover it with a piece of aluminium foil to prevent burning.
- Let the cake cool completely before releasing and removing the springform.
Video
Notes
Nutrition
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Sal
Lovely!
Kat
I absolutely love this cake! A friend gave me a box of (non-keto) fruit so I have made the cake with plums and with apples (divine!) and will make another one with apples and quinces. Thank you so much for this recipe!
Katrin Nürnberger
So glad you are enjoying it! Love the idea of making it with quince - delicious.
Lesley
Love this cake - made it a few times with rhubarb from the garden. Simple and quick, tasting delicious Do you know if it freezes ok please?
Katrin Nürnberger
Yes, it freezes well. Glad you like it!
Martin
Just made this, but once it was in the oven, I remembered that I had forgotten the cream cheese!! It looks OK, just waiting for it to cool down so I can try a slice.
Katrin Nürnberger
Hope it'll still taste good! If it looks ok, it will probably be fine 🙂
martin
Hi Katrin, yes it tastes fine, i thought it would be a bit dry, but it is still quite moist.
Chef Angela
Love
Love
Love this!!! Perfect crumb! I added toasted pecans & use a homemade vanilla vodka extract in mine… it was Devine!
Ellen
Dear Katrin/Liebe Katrin!
Happy Birthday or Herzliche Glueckwuensche zum Geburtstag! Ich wuensche Dir ein tolles WE in Lisbon!
I love this recipe, especially the base which I use as my base cake for all sorts of stuff.
Ihave made it with rhubarb but find it is not necessary to macerate it first with the sweetener but just lay the pieces on top fresh from the garden. Instead of crumble on top I have also made it with a sourcream/or yogurt and cream cheese/eggs, sweetener and vanilla mixture that I pour on top and bake. In Germany it is made with „Schmand“ a sort of thicke sourcream. You are likely familiar with it. I also use sourcream instead of the creamcheese as it blends in better. I noted you use yoghurt in your olive oil cake.
I have also made it with rasperries.
As well I now use the base cake recipe for fresh strawberry cake, baking the batter in a 10inch springform pan (cake is about 1 inch thick) or a large rectangular springform pan for a thinner base. I use this as an „Obstboden“ or fruit bottom cake and then lay fresh fruit, sor far usually strawberries on top whole sitting upright or nestled into a laye of vanilla pudding (Simply Delish) or just plain sourcream. I don‘t bother with a glaze and serve it right away.
SErve with unsweetened whicpcream with a touch of vanilla and everybody is happy!
I have served this mostly for non keto‘ers and they all ask for seconds and the recipe!
Thanks for all your work in developing your yummy recipes for us! Vielen Dank!
I am from Mainz (1970) and now live in beautiful Nova Scotia.
Katrin Nürnberger
Thank you for all your suggestions, sounds amazing! I especially love the idea of the “Obstboden”.
Ellen
Love this cake. Lately have changed the Streusel topping to a cheesecakey mix of 1 package cream cheese (or mascarpone) 1/2 cup sour cream, tsp vanilla, 3 tbsp erythritol and 2 eggs. Beat and spread over the rhubarb on the cake. Keep an eye on cake while baking. May require a cover with foil to keep from burning. I use a 9 inch springform for a thinner cake. I also don't macerate the rhubarb but cut it up directly from my garden and nestle on top of the batter then spread the cheese/ sour cream mixture over it. This is a common variation in Germany. Another one is to bake it sans topping just with rhubarb then top with a meringue and bake til browned. Also yummy.
Katrin Nürnberger
Hi Ellen, these are both wonderful ideas. I love the idea of a rhubarb cake with cheesecake topping. Thank you so much for sharing.
Luna
It’s wonderful such a treat. Thank you!!
Stacy
I made this yesterday for Mother's Day in Canada and I can't believe how well it turned out. This didn't even taste like a keto cake but just a regular delicious rhubarb coffee cake. I might try adding a bit more rhubarb next time because I love the flavour so much. I added a bit of salt to the cake batter which worked out.
ShelBel
Katrin the cake mix itself was delicious (like a pound cake) and with the bonus rhubarb on top it has now became one of my favorite cake recipes. Mine came out perfect in the 8" springform pan. I appreciate your Notes, and used "golden" erythritol monk fruit blend, and your tip to run a knife around the edge before cutting or opening up the springform was a life saver to keep the cake from falling apart. Since I have more rhubarb I will be making this again!
*Have you tried adding additional rhurbarb to the cake mix??? I would like to give it even more of that rhubarb flavor.
Katrin Nürnberger
Glad you like the recipe! I think you can definitely add some more rhubarb into the batter. It may make the cake more fragile, so best wait until it's fully cooled before cutting.
A butler
This is a most amazing recipe! Thank you so much
Katrin Nürnberger
So happy you like the cake!!
Marie
Hi, I am just wondering why it is called a rhubarb COFFEE cake when there is no coffee in it. Going to make it tomorrow
Katrin Nürnberger
Hi the definition of a coffee cake is that you eat it with a coffee - in the afternoon when it's "coffee time".
Pam
I don’t keep almond milk in the house. Could I use 2% milk or maybe heavy cream in place of the almond milk?
Katrin Nürnberger
I would replace it with the dairy milk.
Pam
Thank you for your response
Helen
This looks great - I only have frozen rhubarb, Would using frozen rhubarb ruin the cake?
Katrin Nürnberger
No, I think it would also work. I would defrost it first, drain any liquid and then macerate it as per recipe.
Lili
Can I omit the rhubarb?
Katrin Nürnberger
Sure!
Lindsey Park
Could you do this with apple?
Katrin Nürnberger
Yes, definitely. You could just use it raw. It would add carbs though - rhubarb is a very low carb fruit, unlike apple.
Janet Huyton
Hi - picked about 5 lbs of rhubarb yesterday so eager to try this!! Do I drain the fruit after mascerating please? Thanks, love your recipes. xxx
Katrin Nürnberger
Yes, once you mix it with the sweetener it starts to release a lot of liquid. Drain it off before you use the rhubarb in the cake.
Janet Huyton
Lovely, thanks, after weighing it after I cut it all up and cleaned it etc there is more like 7lb!!
Katrin Nürnberger
Wow! Make some compote or rhubarb jam...just cook it down and add sweetener and ground chia seeds like I did in the sugar free strawberry jam recipe! (You would need a lot more sweetener as rhubarb is so sour!)
Janice
Made this yesterday. It is fantastic! I have enough rhubarb for another batch and thought I'd try making it into muffins.
Katrin Nürnberger
That's a great idea. These should be done in about 25 minutes.
Janice
Just took the muffins out of the oven. Can’t seem to copy and paste a photo. They look great! Started with 20 minutes. They weren’t done but topping was starting to brown so I laid a piece of foil over top. Did 5 more minutes. Still had a few crumbs on the tester so 2 more minutes. Breakfast tomorrow! Cake is 12 servings and I got 12 muffins.
Katrin Nürnberger
That sounds perfect! I always love the in-built portion control of muffins 🙂
Deb
Your timing was PERFECT...had all the ingredients to make this today. We loved the combination of cream cheese in the cake and the rhubarb with streusel. Just lovely. A new favorite.
Katrin Nürnberger
Oh that's so good to hear! Really glad you liked it!
Lise
Delicious
Cherry
Is this supposed to be called coffee cake as I can't see coffee anywhere in ingredients list or method? I'm just wondering if it's supposed to have coffee in as thinking about making this today? Thanks
Katrin Nürnberger
It has no coffee in it - but it's an ideal cake to enjoy with a cup of coffee (or tea).
Athina Levesque
Coffee cake never has coffee in it. It’s called coffee cake because it’s usually eaten with a cup of coffee.