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Why This Rhubarb Buttermilk Cake Recipe Works
Every spring in Iowa, as soon as the rhubarb starts pushing up in the garden, I know this recipe won’t be far behind. Growing up, my mom would head out to our rhubarb patch, come back with an armful, and this rhubarb buttermilk cake was one of the first things she baked. It actually started with my great-grandma, who was a master of never wasting any produce. She had extra buttermilk from churning butter and more rhubarb than she could can, so this cake was the answer.
Over the years, I’ve updated the recipe to make it as simple and reliable as possible for a modern kitchen. The batter mixes up quickly, the rhubarb is folded in, and the cinnamon sugar topping adds a crackly finish that makes every slice feel special. It’s the kind of dessert you can bake on a weekday, share with neighbors, or stash in the freezer for when family drops by — just like my grandma would have done.
Here’s why you will love this rhubarb cake:
- A one-bowl batter that’s easy to mix together.
- Tender, moist crumb from the buttermilk.
- Rhubarb pieces in every bite.
- Cinnamon sugar topping that bakes into a crackly crust.
- Perfect for springtime brunches or as a simple coffee pairing.
Rhubarb Buttermilk Cake Ingredients
Each of the ingredients needed to make this rhubarb cake is needed to create the perfect texture and flavor:
- Unsalted butter – Room temperature butter creams easily with the sugars, which gives the cake structure and a tender crumb.
- Granulated sugar – Used to sweeten the batter and used with cinnamon to make a crispy topping.
- Light brown sugar – Adds a bit of molasses flavor and moisture.
- Eggs – Bind the batter together and add richness.
- Vanilla extract – Amps up the flavor of the cake and balances the tart rhubarb with a cozy aroma.
- All-purpose flour, baking powder, and baking soda – Form the structure of the cake so it can hold the pieces of rhubarb without getting heavy.
- Kosher salt – Balances the sweetness and brings out the flavor of the rhubarb and warm spices.
- Buttermilk – Adds tangy flavor and moisture, which helps keep the cake soft.
- Rhubarb – Cut into small bite-sized pieces, it adds tart pockets of flavor and some pretty pops of color throughout the cake.
- Ground cinnamon – Adds gentle warmth and a nostalgic coffee cake flavor to the top of each loaf.
The full amount of each ingredient can be found in the recipe card below.
How to Make Rhubarb Buttermilk Cake
There are 5 easy steps to put together this buttermilk cake:
Step 1: Prep – Preheat the oven to 350°F. Butter two 8 ½ x 4 ½ inch loaf pans and set them aside.
Step 2: Prepare the wet ingredients – In a large mixing bowl, combine the softened butter, granulated sugar, and light brown sugar. Using a whisk or mixer, beat until the mixture is light and fluffy, 2-3 minutes. Add one egg and mix until fully incorporated. Then, add the second egg along with the vanilla extract, mixing until smooth.
Step 3: Finish the batter – To the bowl, add the flour, baking soda, baking powder, and kosher salt. Mix gently just until the dry ingredients are mostly combined with the butter mixture. Slowly add the buttermilk while folding with a spatula or mixing on low speed. Continue just until the batter is smooth, thick, and no streaks of flour remain. Add the chopped rhubarb to the batter. Use a spatula to fold it in gently so the pieces are evenly distributed without overmixing. Divide the batter evenly between the two prepared loaf pans. Use the spatula to spread the tops into an even layer.
Step 4: Make the cinnamon sugar topping – In a small bowl, mix together the granulated sugar and ground cinnamon. Then sprinkle the mixture over the batter in each pan.
Step 5: Bake the cakes – Place the pans in the preheated oven and bake for 45-55 minutes, until the tops are deep golden and a skewer or toothpick inserted in the center comes out mostly clean with a few moist crumbs. Remove the cakes from the oven and let them cool in the pans for 20 minutes. Run a knife around the edges and turn out onto a rack to cool.
Recipe Tips
- Keep the rhubarb pieces small – Aim for ¼-inch pieces so the rhubarb softens completely in the bake and stays nicely situated within the crumb instead of sinking or staying crunchy. If your rhubarb stalks vary in width, slice the extra-wide ones in half to ensure the rhubarb bakes evenly in the cake without losing its crunchy texture.
- Use room temperature butter – Let the butter sit out for 1-2 hours before baking so it creams easily with the sugars and gives you a fluffy, well-mixed batter.
- Do not overmix once the flour is in – Mix just until the flour disappears. Overmixing can make the cake tough and can cause the rhubarb to break down too much.
- Watch for visual cues, not just time – Ovens vary, so start checking at 45 minutes. The loaves should be deeply golden, slightly cracked on top, and a skewer should come out mostly clean.
- Let the cakes rest before slicing – Giving the loaves at least 20 minutes to cool allows the crumb to set so the slices hold together, and the rhubarb juices stay in the cake instead of running out.
Frequently Asked Questions
The cake can easily be made in a Bundt pan, which will produce larger pieces.
Fresh rhubarb does work best for this recipe, but if you need to use frozen rhubarb, make sure to let it thaw and drain completely.
Nuts would not be a great addition alongside the texture of the rhubarb. I would advise skipping the addition of any nuts.
Of course! For easy storage, simply slice the cake into individual pieces and freeze those, using parchment to divide the pieces. When ready to eat, let the pieces thaw at room temperature until tender.
Follow These Tips
Serving
Once the cake has cooled, slice it into pieces and serve it with coffee or tea for breakfast or brunch. Add a dollop of lightly sweetened whipped cream or a scoop of vanilla ice cream for a simple dessert.
Storage
Room temperature – The cake slices can be stored in an airtight container for 2-3 days.
Refrigerate – Once completely cooled, store slices or whole loaves in an airtight container in the refrigerator for up to 4 days. For the best texture, bring refrigerated slices to room temperature before serving or warm them gently.
Freeze – Slice the cooled loaves and place parchment paper between the slices to prevent sticking. Store in a freezer-safe container or bag for up to 3 months.
Reheat – Thaw frozen slices at room temperature for 30-60 minutes, or in the refrigerator overnight. Warm in the microwave for 15-20 seconds, just until the crumb is soft. You can also warm them in an oven, if desired.
More Rhubarb Recipes
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Rhubarb Buttermilk Cake
Ingredients
- 8 tbsp (1 stick) unsalted butter room temperature
- ½ cup granulated sugar
- ½ cup light brown sugar
- 2 large eggs
- 1 tsp vanilla extract
- 2 ½ cups all-purpose flour
- ½ tsp baking soda
- 1 tsp baking powder
- ½ tsp kosher salt
- 1 cup buttermilk
- 2 cups chopped rhubarb
For the topping
- ¼ cup granulated sugar
- 1 tsp ground cinnamon
Instructions
- Prep: Butter two 8 ½ x 4 ½-inch loaf pans and set them aside. Preheat the oven to 350°F.
- Prepare the wet ingredients: In a large bowl, combine the butter, white granulated sugar, and brown sugar. Using a whisk or a mixer, beat the mixture until light and fluffy, 2-3 minutes. Add one egg and mix to incorporate. Repeat with the second egg and vanilla extract.8 tbsp (1 stick) unsalted butter, ½ cup granulated sugar, ½ cup light brown sugar, 2 large eggs, 1 tsp vanilla extract
- Finish the batter: To the wet ingredients, add the flour, baking soda, baking powder, and salt. Whisk to combine and slowly add the buttermilk while folding. Once the buttermilk is added, add the chopped rhubarb and fold until it is just mixed in. Pour the batter into the two prepared loaf pans and spread the top of each one to an even layer.2 ½ cups all-purpose flour, ½ tsp baking soda, 1 tsp baking powder, ½ tsp kosher salt, 1 cup buttermilk, 2 cups chopped rhubarb
- Make the topping: In a separate bowl, mix together the white granulated sugar and cinnamon, and sprinkle the mixture evenly over the two cakes.¼ cup granulated sugar, 1 tsp ground cinnamon
- Bake at 350°F for 45-55 minutes until golden brown and a skewer inserted into the middle comes out clean. Once baked, remove the cakes from the oven and allow them to cool for 20 minutes before slicing.
Video
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Did you make this? Leave a comment below!
Styling: Addelyn Evans | Photography: Dera Burreson
I made this recipe for the first time. I did 1.5 batches and baked it in a 9×13 cake pan. It was delicious! My family loved it. Another wonderful recipe from Kaleb! Thank you for sharing them with us Kaleb.
Delicious and moist. Salting the rhubarb and letting it rest for about 60 minutes to pull the excess moisture out and discard it was fabulous! The loaf has a nice fluffy cake like texture.
I’m already planning to make it again tomorrow in a bundt pan to take to my mom’s care home for the residents to try. I’m sure many of them had their own rhubarb patches in their lifetime. Thankyou so much for another great recipe. LP
Best rhubarb cake ever
Made this cake in an Angel food cake pan. It was delicious. Next time I will add 1 cup more of diced rhubarb. Flipped the cake out on a plate then slid on a cake pedestal .
Made this today. It was excellent. Everyone loved it. My 92 yr old father (who has a sweet tooth) and 88 yr old mother both told me to keep it on rotation. Thank you for a wonderful recipe. Made this as 1 large loaf and it worked perfect.
Hello! I am on an aromatase inhibitor as part of my breast cancer treatment. As rhubarb is rich in Vitamin K, this vegetable helps to keep bones strong, so helpful in taking this type of medication.
This cake is delicious, fun to bake, and so good for us! Thank you for sharing this wonderful recipe!
Delicious!
Thanks
This was delicious! Nice and light… had people who normally don’t like rhubarb eating it! Definitely will make again😊
Delicious. I used 3cups of rhubarb because that is what came in from the garden and I wanted more pieces per slice. I was wary of the salt as we use it sparingly, but it was fine. Got maybe 3T of liquid. I can understand about the gummy issue, but this seemed to solve it. Will definitely be making this again.!
Loved the cake! It’s very similar to one my mom made when I was growing up. Will try to macerate the rhubarb with sugar next time though, it tasted a little salty. Mom used to make in a 9 x 13 pan, it did get soggy when she made it. Getting some of the water out of the rhubarb helped greatly! Thank you for a great recipe!