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Rhubarb Breakfast Cake (Gluten-free, sugar-free)

rhubarb cake gluten free

Disclosure: this cake started as a Peach Breakfast Cake but since my first attempt with peaches I made some improvements to the batter and I wasn’t able to find organic peaches anymore. One day I saw rhubarb in stores (it’s popular here in Denmark) and I felt it could be a good fit. And oh wow, that was perfect. So Rhubarb Breakfast Cake it is.

However, I know in many places peaches season started (oh Texas peaches!!), so feel free to replace rhubarb with peaches. In fact, what is so great about this cake is that it can be made with different fruits. I only tried peaches, apples and rhubarb, but I’m thinking cherries and plums will work really well.

The mix of lectin-free, gluten-free flour for the rhubarb breakfast cake

The mix of flour I used for this cake is made of chestnut, tigernut and coconut. I know chestnut is a bit of a pain to find in the US, but Amazon sells it, as well as It might be a little more expensive but you will save on sweetener because chestnut flour is sweet. It’s totally worth it.

In Europe, chestnut flour is common in gluten-free baking so it can be found more easily in supermarkets or specialty stores. It’s also less expensive because the one you usually find in the US is imported from Italy – where chestnut flour is common and used in specific dessert recipes.

I guess you are much more familiar with tigernut flour. In the US, I love Oragnic Gemini brand (no affiliation). Despite the name, tigernuts are not nuts, but small tubers. Both chestnut and tigernut are very nutritious, albeit a bit carby. Again, in my world, totally worth it.

Rhubarb Breakfast Cake

Chestnut flour and tigernut flour are naturally sweet and very flavourful. So there is not much need for added sweeteners or flavors. I did use one teaspoon of local honey, but you can use yacon syrup or another sweetener of your choice. I call this a rhubarb breakfast cake for a reason. It doesn’t have to be extremely sweet.

I also recommend reading my article Quick guide to lectin-free, gluten-free flours for more information on the different types of flours available.

Rhubarb is packed with nutrients

Rhubarb is not even a fruit, is a vegetable, is very low in calories and is packed with nutrients such as vitamin B, C, and K protein dietary fiber, magnesium, manganese, potassium, calcium, beta-carotene, zeaxanthin, and lutein. I think that’s another reason a breakfast rhubarb cake makes total sense.

If you ever tried rhubarb before you know it has a sour taste profile. Very fresh and crisp, I would say. So traditionally, a lot of sugar is added to rhubarb in desserts. In Denmark, rhubarb jam is very popular but made with a lot of sugar.

That’s why I love the combination between all these types of flours that have an earthy, sweet taste profile and the tanginess of rhubarb. However, if you want more sweetness, you can always drizzle some yacon syrup or even local honey on top.

Other ingredients are coconut milk, coconut flour and shredded coconut and hazelnut butter, so everything is tasty and naturally sweet already. If you don’t find hazelnut butter, you can use pecan or any nut butter you have. Or even make your own.


I get a lot of questions about substitutions. While sometimes substitutions are easy to make, when I develop a recipe with a certain combination of flour is because I choose the types of flour-based on the taste and texture I want to get. I can’t personally recommend a substitution in this case, but a reader told me she made the cake with hazelnut flour instead of chestnut flour and it worked well. However, someone else told me they tried almond flour and it didn’t work so well. Feel free to experiment and leave a comment so other people get inspired to try (or not).

The size and the dish

The size of this rhubarb breakfast cake is about 6, 7in diameter which makes about four portions. I use a ceramic tart dish, similar to this one. For me, it makes four servings. You could also use small, individual dishes. If you double the quantity, you can make it in the full-size pie or tart dish. But since this cake should be flipped after cooked, I’d recommend a smaller size to make sure the cake doesn’t break.

So far I made this cake three times and I never had a problem while flipping it. Just make sure you add a generous quantity of coconut oil to the dish before you add the fruits and the batter.

About measurements

Now about measurements. Forgive me but now I’m in a camping type of living situation. We just relocated from Dallas to Denmark and although I have a fully equipped kitchen (thank God!), things are basic and more… well, European. I don’t have measurement tools yet and I won’t buy any since I have mine coming in a container in about a month.

The measurement cup I have only has grams and I don’t feel like giving you measurements in grams without a scale, as different gluten-free flours tend to have different weights. So I went the old style (what my mom used to do) and use a soup/teaspoon, like the one you use to eat soup or the one to eat dessert or stir a tea. This works well because the quantities are so small, it would be hard to measure with a cup. Luckily, this recipe is pretty forgiving. If you have too much flour you can always add a little bit more coconut milk. I created this image to have an idea of what I consider one tablespoon in this case.

One tablespoon flour

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Rhubarb Breakfast Cake (Gluten-free, sugar-free)

1 Star2 Stars3 Stars4 Stars5 Stars (9 votes, average: 4.78 out of 5)
By Claudia Curici Serves: 4
Prep Time: 10 minutes Cooking Time: 30 minutes

A delicious morning treat that is easy to make using a variety of seasonal fruits.


  • 1 tablespoon coconut oil, for greasing the dish
  • about 6 rhubarb sticks, chopped in 1/2 inch pieces (or more to fully cover the bottom of the dish)
  • 4 tablespoons chestnut flour
  • 4 tablespoons tigernut flour
  • 1 tablespoon coconut flour
  • 2 tablespoons shredded coconut
  • 3/4 teaspoon baking powder
  • pinch of salt
  • 1 big pastured-egg
  • 2 tablespoons hazelnut butter
  • 1 teaspoon honey (or another sweetener of your choice), more if you have a sweet tooth
  • 1 teaspoon vanilla extract
  • 12-15 tablespoons full fat coconut milk



Preheat the oven to 350F.


Prepare the dish by generously coating it with coconut oil and arrange the rhubarb pieces on the bottom of the dish to fully cover it.


Mix the dry ingredients in a small bowl.


In a bigger bowl, combine the egg with the nut butter, honey and 10 tablespoons of the milk and mix well with a hand blender. Start adding the flour and incorporate it into the liquid. When you are done with adding the dry ingredients, you can add more of the coconut milk and combine well until you get a creamy batter that won't be easy to pour but it won't be too solid either. You can pour from the bowl in the dish with the help of a spoon. Level the batter and bake the cake on the middle rack for about 30 minutes.


Let it cool for about 20 minutes before you turn it upside down, with the help of a plate. Check first the sides to see if there is any resistance. Place a flat plate on the top of the cake and turn everything upside down. Lift the baking dish carefully. This cake should come out easily from the dish if the dish is well greased. Serve warm or cold, I love it both ways.


Please read the entire post before you start.

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  • Reply
    June 5, 2020 at 6:44 am

    I can’t find tigernut flour, what could I replace it with? Thank you x

    • Reply
      June 9, 2020 at 5:19 am

      It’s hard to make recommandations of substitutions when I have not tried it myself. Please read the paragraph about substitutions and see the two examples I gave, based on feedback from people who have tried to substitute. Best way is to experiement depending on what you have available. I would say almond flour would work, someone said they tried and failed… So I don’t know until I try it myself.

  • Reply
    December 29, 2020 at 11:15 am

    Made this as a Christmas morning treat with apples instead of rhubarb and it was absolutely delicious! I subbed hazelnut flour for chestnut flour and it worked well I think, though I did have to cook it a little bit longer than 30 minutes.

    • Reply
      December 29, 2020 at 11:45 am

      Thank you Greta! Good to know hazelnut flour works well. I think I’ll do the same for NYE. <3

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