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My mom has been making this cake ever since I was a child. This rhubarb cake recipe was passed down to her from my grandmother, my mom’s mom, and the last time I was home, I made a decision that I think you, my wonderful community, will really appreciate.
My mom is going to be 78 this coming January. It is so hard to believe. She is in good health, unless you ask her; her body is strong, bad knees and all, and she is sharp as a tack, thank goodness for that. My stepdad just had his shoulder replaced and is already raring to go, so between the two of them, they plan to live a whole lot more life. Something I am incredibly grateful for.
My grandmother passed away many years ago, but we spent loads of time together. My mom was the only girl, but she had five brothers. A good old-fashioned Irish Catholic family. My mom grew up on a farm. They did not have running water, and from what I have been told, everyone bathed in a tub on Saturday night, and the last person in got the dirtiest water. Horrifying, but also, what a time.
My grandmother made everything from scratch. Bread, pastry, butter, preserves, the whole lot. There was not a lot of money, and there were a ton of mouths to feed, but they made it work. My mom’s job was to retrieve the eggs from the chicken coop, which she really did not love. Constantly being pecked by hens does not exactly sound like my dream chore either.
I remember my grandmother’s recipe books. Covered in flour, stained by lard, pages stuck together from sticky fingers and years of use. There is something so beautiful about recipes like that. They are not just instructions. They are history.
The last time I was home, my mom made her rhubarb cake. Rhubarb grows wild in Ontario, and there always seems to be too much to eat. My mom loves it and makes rhubarb preserves to have over the winter months, which is just another thing she learned from her mother. As we ate the cake, my mom looked at me proudly and said, “I used only maple syrup to sweeten this cake.” She then told me that when her mother made it, she added two cups of white sugar. Two whole cups!!!
I sat there with my mouth ajar because I could not imagine adding two cups of sugar to anything. That was the moment it came to me. Could I recreate some of my grandmother’s old recipes and make them healthier? I thought this could be fun, delicious, and a beautiful way to connect back to my Grandma Doyle. So here we are, starting with this healthy rhubarb cake recipe!
This is my version of an old-fashioned rhubarb cake recipe, but with a few modern updates. Instead of two cups of white sugar, we are using ripe bananas and coconut sugar for sweetness. Instead of making it overly heavy, we are keeping the crumb soft and tender with buttermilk and olive oil. The rhubarb still does what rhubarb does best: it brings that bright, tart, almost jammy bite that makes this cake so special. This is not a sugar-free cake, and it is not trying to be. It is still cake. But it is a more balanced, more nourishing version of a family classic, and that is the sweet spot I love.
A healthy rhubarb cake should still taste like cake. It should still feel cozy and nostalgic. It should still make you want another square. This one does all of that while using ingredients I feel good about. It’s tender, tart, and lightly sweet, topped with a simple cinnamon-coconut sugar topping that gives the whole thing a little sparkle!
Rhubarb is one of those ingredients that feels very old school, in the best way. It is tart, bright, and technically a vegetable, though we almost always treat it like fruit in baking. Rhubarb is naturally low in sugar, high in fibre, and contains antioxidants and vitamin K. It is also one of those seasonal ingredients that instantly make a recipe feel seasonal because it’s not always available fresh!
No, you do not need to cook rhubarb before adding it to this cake. For this simple rhubarb cake recipe, the rhubarb is chopped and folded directly into the batter. As the cake bakes, the rhubarb softens and releases its juices, creating little pockets of tart, jammy flavour throughout the cake. That is part of what makes this rhubarb cake so easy. No pre-cooking, no extra pot, no unnecessary steps. Just chop it, toss it into the dry ingredients, and let the oven do the work.
Preheat your oven to 350°F. Line an 8×8 pan with parchment paper so the cake is easy to lift out once it has cooled.
In a large measuring cup, add the buttermilk. Stir in the baking soda and let it sit for about 10 minutes. This gives the baking soda time to react with the buttermilk’s acidity.
After 10 minutes, add the olive oil, vanilla, and egg to the buttermilk mixture. Whisk until everything is combined. Then add the mashed bananas and stir again. The mixture will look creamy, slightly thick, and a little rustic from the banana. That is exactly what we want.
In a large bowl, combine the flour, coconut sugar, and salt. Add the chopped rhubarb and toss it through the dry ingredients with your hands or a spoon. Coating the rhubarb in flour helps keep it evenly distributed in the batter. Coating the rhubarb also keeps it from slipping to the bottom of the pan while baking, so make sure each piece is covered.
Pour the wet ingredients over the dry ingredients. Mix well, making sure there are no dry pockets of flour remaining. The batter will be thick and full of rhubarb. Do not overthink it, but do make sure everything is properly combined. Pour the batter into the prepared pan and smooth the top with a rubber spatula. In a small bowl, stir together the coconut sugar and cinnamon. Scatter it evenly over the top of the cake.
Bake for 40 minutes, or until the cake is set, golden, and a toothpick inserted into the centre comes out mostly clean. The top should look golden brown, the edges should be slightly pulled away from the pan, and your kitchen should smell like someone’s grandmother came over and blessed the house with sugar and spices!
Allow the cake to cool for at least 30 minutes before serving. This helps the crumb settle and makes it easier to slice. Serve with ice cream, Greek yogurt, or just as is with a cup of coffee.
Store this moist rhubarb cake in an airtight container at room temperature for one to two days, or in the fridge for up to five days. Because the cake is moist from the bananas, olive oil, buttermilk, and rhubarb, I prefer storing it in the fridge if I am keeping it for more than a day. You can also freeze it. Slice the cake into squares, wrap them individually, and store them in a freezer-safe bag or container. Thaw in the fridge overnight or on the counter when you are ready to enjoy.
If you love grandma’s baking, you’re going to love this cake! Also, if you love rhubarb, you’re going to be obsessed. This cake tastes classic but has been brought up to the times and supports your health instead of targeting it! It has all the charm of an old-fashioned family recipe, but with a healthier twist. It is the kind of cake you can serve for dessert, but also the kind of cake I fully support eating with Greek yogurt for breakfast. No judgment here. Honestly, that sounds like balance to me.
Can I make this cake with frozen rhubarb? Yes, you can make this cake with frozen rhubarb. I prefer fresh rhubarb for this recipe, but frozen will work if that is what you have or you’re making it out of season. For best results, do not thaw it completely before adding it to the batter, as thawed rhubarb can release a lot of liquid. Chop it if needed, then toss it into the dry ingredients just like fresh rhubarb.
Is this a healthy rhubarb cake? This is a healthier take on an old-fashioned rhubarb cake. It uses bananas and coconut sugar for sweetness, olive oil for moisture, and fresh rhubarb for tart flavour. It is still cake, but it is made with more thoughtful ingredients.
Can I make this cake gluten free? Yes. Use a high-quality gluten-free 1:1 flour blend in place of regular flour. Make sure the blend is intended for baking and contains binders such as xanthan gum for the best texture.
Can I make this cake dairy free? It’s definitely possible by using a dairy-free milk with apple cider vinegar in place of buttermilk. Let it sit for about 10 minutes before using.
Do I need to peel rhubarb? No, you do not need to peel rhubarb. Just trim the ends, wash it well, and chop it into small pieces.
I would love to get your feedback in the comments below! Don’t forget to review and say thank you to Grandma Doyle! I hope I did you proud.
If you loved this easy rhubarb cake, try these healthy desserts next:
High Protein Vanilla Birthday Cake
Food Photographer and Recipe Developer based in Toronto, Canada.
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*Macros are provided as an estimate for convenience. Your final numbers will vary depending on ingredient brands, substitutions, and how you portion the recipe.
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