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This Rhubarb Coffee Cake is a delicious and easy-to-make recipe, perfect for springtime baking. The tart and tangy rhubarb is balanced by the sweetness of the cake and a rich, buttery crumb topping!
I grew up just a 3-mile bike ride down the gravel road from my grandparents. Therefore, my siblings and I were there quite frequently….stopping down on our bikes, dirt bikes, four-wheelers…you name it. Grandma always had delicious treats for us.
Most of the time, her freezer was full of Buttermilk Cookies or Kolaches. But in the late spring, when rhubarb was in season, she enjoyed making different recipes with her bountiful rhubarb plants.
A Sweet and Tangy Rhubarb Coffee Cake
When I made this coffee cake, I thought of her and wished I was still just a 3-mile drive away. Now a 3-hour car ride separates us, but I think of her all the time, especially when rhubarb is in season! Though her Rhubarb Muffins are always a hit and a long-time family favorite, this Rhubarb Coffee Cake is sure to rival them. And despite its name, coffee cake doesn’t actually have coffee in it—it’s traditionally meant to be enjoyed alongside a cup of coffee. I’m not a coffee drinker, though, so I’ll happily have a glass of milk on the side instead, haha!
Key Ingredients
The full list of ingredients and amounts are in the recipe card below, but I wanted to draw attention to a few of them.
- All-Purpose Flour – I used all-purpose flour for this recipe, but one reader reported great results using a cup-for-cup gluten-free flour substitute.
- Buttermilk – If you don’t have any buttermilk, you can make your own sour milk instead! (see notes in recipe card below)
- Rhubarb – You can use fresh rhubarb or frozen rhubarb. If you do use frozen rhubarb, be sure to defrost it and drain the excess moisture (do NOT squeeze it, though!).
How to Make Rhubarb Coffee Cake
Streusel Topping
This topping is super simple to make. You’ll just add the flour, brown sugar, cinnamon, and melted butter to a bowl and stir until combined. Then, refrigerate until the batter is ready. Giving it a chance to chill will help give you an extra crunchy, delicious topping.
Coffee Cake Batter
First, you’ll stir together the dry ingredients and set them aside. Then, cream the softened butter and sugars in a large bowl with an electric mixer (or stand mixer) until light and fluffy. Then you’ll add the eggs and vanilla and mix until combined.
Next, you’ll add about half of the dry ingredients (don’t worry about getting it exact, just eyeball it!) and stir until just combined, followed by the buttermilk. Once the buttermilk is mixed in, add the rest of the flour mixture and stir just until combined.
Assemble the Cake & Bake
Scoop about half of the cake batter into the greased square pan and spread to an even layer. You can use either a metal or glass pan, but note that they’ll bake up differently because metal heats up and cools down more quickly, while glass retains heat longer and can continue baking the cake even after it comes out of the oven. I prefer to use a light metal pan for reference.
Top with the diced rhubarb and about 1/2 cup of the streusel topping. Spoon the rest of the batter on top and gently spread. Don’t worry if it mixes with the streusel a bit – it all bakes together anyway! Lastly, top with the rest of the streusel and bake!
When baking the coffee cake, be sure to check it at around 25 minutes. If it’s getting brown on top, but isn’t set in the center, I recommend covering it with aluminum foil for the remainder of the bake. This will help the inside bake without it overbrowning. Once it’s done, let it cool on a wire rack.
How to Store Leftover Coffee Cake
Let the coffee cake cool to room temperature, then store it in an airtight container.
Can I Freeze Coffee Cake?
Absolutely! If you plan to serve the coffee cake more than two days after baking, simply wrap it well and freeze it. Thaw it at room temperature before serving.
Other Rhubarb Recipes I Love
🩷Rhubarb Cookies
💚Rhubarb Cake with Vanilla Butter Sauce
♥️Rhubarb Custard Bars
💛Rhubarb Dump Cake
Rhubarb Coffee Cake
Equipment
- One 8×8 or 9×9-inch pan
Ingredients
Streusel Topping
- 1/2 cup flour
- 2/3 cup brown sugar
- 1 teaspoon cinnamon
- 1/4 cup butter melted
Coffee Cake Batter
- 1 3/4 cup flour
- 1 teaspoon baking powder
- 1/2 teaspoon baking soda
- 1/4 teaspoon salt
- 6 tablespoons butter softened
- 1/2 cup sugar
- 1/4 cup brown sugar
- 2 eggs
- 1 teaspoon vanilla
- 1/2 cup buttermilk*
- 1 1/2 cups diced rhubarb
Instructions
- Preheat oven to 350°F and grease or line an 8×8-inch or 9×9-inch square baking pan with parchment paper; set aside.
Make the Streusel Topping
- In a small bowl, combine the brown sugar, cinnamon and flour.
- Add the melted butter and stir until combined; refrigerate until ready to use.
Make the Batter
- Add the flour, baking powder, baking soda and salt to a bowl; stir and set aside.
- Add the butter and sugars to a large mixing bowl or a the bowl of a stand mixer.
- Cream the butter and sugars for a couple minutes, or until light and fluffy.
- Add the eggs and vanilla; stir well, scraping down the sides at least once.
- Add about half of the dry ingredients and mix to combine.
- Continue mixing while adding the buttermilk slowly; scrape the sides of the bowl.
- Add the remaining dry ingredients, stirring until just combined.
Assemble and Bake
- Pour a little more than half of the batter into the prepared pan; spread to an even layer.
- Sprinkle the rhubarb over the batter and then about 1/2 cup of the streusel topping.
- Spoon the remaining batter on and smooth it out to an even layer.
- Top with the streusel topping, pressing it into the batter gently.
- Bake for about 30 minutes, or until a toothpick inserted in the center comes out with just a few moist crumbs (not runny batter). If the top is browning but the cake isn't done in the center, top with aluminum foil and continue to bake. This will keep it from over-browning.
- Let cool, then cut and enjoy!
This cake was delicious and I made it exactly as the recipe was written. I loved that the rhubarb goes in a layer between the two layers of batter as opposed to the mixing it all in. The cake was spongy, moist and not overly sweet with just enough cinnamon in the topping to complement the rhubarb and not detract from the taste of it. The crunchy streusel topping is the bomb and i could eat that on everything, lol. Thanks for such a great recipe it and it will be my go to during rhubarb season.
Best Rhubarb Coffee cake ever!!!
I have made this several times this summer and it’s the BOMB.
I am gluten sensitive and I make this with my Namaste 1 to 1 Gluten Free Flour Blend. I do put about 3 cups of frozen rhubarb instead of 1.5 cups of fresh. I also add about a 1/4 cup of oats into the mix for the streusel topping. Because I am using GF flour it does take longer to bake, it usually takes about 45 minutes. But be sure to check with a toothpick for doneness. I like to have mine warm with cream over the top. Try it you’ll love it, people I have shared this with don’t know it’s gluten free.
I think this recipe has too much liquid in it, which makes it hard to finish cooking the center. Rethink using baking soda and buttermilk. Rhubarb brings a ton of liquid as it cooks. If you don’t believe me, ask Paul Hollywood.
Good morning – I’ve never had that issue with this coffee cake. Did you use frozen rhubarb? Or add more liquid than listed? As you can see in the process photos, the cake batter is quite thick which compensates for the super moist cooked rhubarb. Others seem to absolutely love this recipe, so I’m not sure what to tell you! 🙂 ~Kelsey
I will make rhubarb cake .. looks good
Absolutely delicious! I used frozen rhubarb and made 1.5x the recipe in a 9×13 pan. I made sure to defrost and drain the frozen rhubarb prior to adding, though I still had to cook the cake for an hour total. Would definitely make again!
Thanks for taking the time to leave a review, I appreciate it so much!! ~Kelsey
This is a terrific cake. The rhubarb melts and the crunchy topping is so good. it did take 50 minutes in my oven.