A lovely choice for brunch or dessert, this super moist blueberry rhubarb buckle is topped with the most delicious cardamom and cinnamon streusel.

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What you’ll love about this recipe
- The streusel! Crowing the moist buckle is the most delicious streusel. The sweet, crunchy, buttery topping is elevated with spices like warming cinnamon and citrusy cardamom.
- It’s prepared with seasonal ingredients! I love preparing dishes with seasonal ingredients. When in season, fresh fruit tastes so much better and is typically more economical. Blueberry season and rhubarb season overlap in the month of June making it the most ideal time of the year to prepare this buckle.
- It’s multipurpose! While this sweet and fruity buckle is most definitely suitable for dessert, it also works for brunch or even breakfast as it is quite similar to coffee cake as well as muffins with streusel.

Ingredients (+ notes & substitutions)
- All-purpose flour: For the cake and the streusel.
- Dark brown sugar: Also for the cake and the streusel.
- Granulated sugar: Again for the cake and streusel, but also for the fruit.
- Cardamom powder: Cardamom is slightly peppery and herbal with notes of citrus that pairs exceptionally well with both blueberries and rhubarb. While I highly recommend it, if you’re not a fan, feel free to omit it.
- Ground cinnamon: This warming spice is a given.
- Unsalted butter
- Fresh blueberries
- Fresh Rhubarb: Although technically a vegetable, the courts legally declared rhubarb a fruit in the 1970s because it is most often treated as one. This makes sense considering that it’s typically incorporated in dessert(ish) dishes like pies and cakes. The reason for this is that it in order to tame the extreme tartness, it is often combined with sugar. This recipe calls for two stalks. I found that most stalks yielded approximately one and a half cups once cubed. The quantity does not have to be exact so should the two stalks result in slightly more or less cubed rhubarb, don’t worry about it!
- Baking powder: For leavening.
- Baking soda: Also for leavening.
- Kosher salt
- Large eggs: You will need one large egg and one egg yolk. The yolks have a higher moisture content in comparison to the whole egg.
- Vanilla extract
- Sour cream: For moisture and tang!
- Whole milk
How to make this blueberry rhubarb buckle (+ tips)
This cake is actually very simple to make. Begin by preheating your oven to 350 degrees. Lightly grease a 9×13″ baking dish and set it aside.
In a medium bowl, combine blueberries, rhubarb, and one tablespoon of granulated sugar and set aside. This process is called maceration. It is useful because it breaks down the fruit; releasing flavor and softening it.

Next prepare the streusel by combining the brown and white sugar, cardamom powder, and ground cinnamon in a medium bowl. Pour in melted butter and stir with a fork until crumbles/clumps form. Place bowl in the freezer until ready for use.

In a medium bowl, whisk together flour, baking powder, baking soda, and salt.
In the bowl of a stand-up mixer fitted with the paddle attachment, add the butter, brown sugar, and remaining white sugar. Cream at medium speed for 3-5 minutes or until light and fluffy, scraping down the sides as needed.
Add the eggs and vanilla and mix until just combined.
Continue mixing and add half of the dry ingredients, followed by the sour cream, then the remaining dry ingredients, and finally the milk. Mix until just combined.
Pour the batter into your baking dish then layer with the fruit.

Top with streusel.

Bake for 45-55 minutes or until golden brown and a toothpick inserted in the middle comes out without any raw batter. I found that 50 minutes was perfect! Allow it to cool for at least five minutes prior to slicing. Serve warm or allow to cool prior to serving.
How to Store
Cover tightly and refrigerate for up to one week.
FAQ
A buckle is a cake with fruit, traditionally blueberries, mixed into the batter that is topped with streusel. As the cake bakes the weight of the fruit causes the cake to “buckle”.
You may have noticed this buckle cake sounds very much like an American coffee cake and it is! They are not, however, the same thing. The main difference is that a buckle has a layer of fruit. Like a coffee cake, it can easily be served as either a dessert or for brunch.
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More fruity baked goods for brunch:
- Apple Chai Spice Muffins with Streusel: Filled with juicy tart apples and topped with a delicious sugary streusel, these soft and moist chai spice muffins are the epitome of fall. Enjoy them with a hot cup of tea or coffee to start your day off right.
- Rhubarb Oatmeal Bars with Vanilla Glaze: Sweet and tart; these simple rhubarb oatmeal bars drizzled with vanilla glaze are the perfect wholesome treat for dessert or even brunch. Naturally vegetarian.
If you make these rhubarb and blueberry buckle I’d love your feedback. Please leave a comment and/or a rating below as I greatly value your opinion. Or snap a pic and tag me on Instagram @taoofspiceblog. Love, light, and happy cooking ya’ll ♥

Blueberry Rhubarb Buckle Cake w/ Cardamom Streusel
Easy, super moist buckle cake with fresh blueberries and rhubarb topped with cardamom and cinnamon streusel. Wonderful choice for brunch or dessert.
Ingredients
Streusel
- 1 cup all-purpose flour
- 1/2 cup dark brown sugar
- 1/2 cup white sugar
- 1 teaspoon cardamom powder
- 1 teaspoon cinnamon
- 1/2 cup (1 stick) unsalted butter, melted
Cake
- 10 ounces fresh blueberries, approximately 2 cups
- 2 stalks rhubarb, cut into 1/2 inch cubes, approximately 3 cups
- 13 tablespoons white sugar, divided
- 2 1/4 cups all-purpose flour
- 2 teaspoons baking powder
- 1/2 teaspoon baking soda
- 1/2 teaspoon salt
- 1/2 cup unsalted butter (1 stick), room temperature
- 1/2 cup dark brown sugar
- 1 large egg + 1 large egg yolk, room temp
- 1 teaspoon vanilla extract
- 1 cup sour cream
- 3/4 cup milk, room temp
Instructions
- Preheat oven to 350 degrees. Grease 9x13 inch baking dish. Set aside.
- In a medium bowl, combine blueberries, rhubarb, and one tablespoon white sugar. Set aside.
- To make the streusel, combine brown and white sugar, cardamom powder, and cinnamon in a medium bowl. Pour in melted butter and stir with a fork until crumbles/clumps form. Place bowl in freezer until ready for use.
- In a medium bowl, whisk together flour, baking powder, baking soda, and salt.
- In the bowl of a stand-up mixer fitted with the paddle attachment, add the butter, brown sugar, and remaining white sugar. Cream at medium speed for 3-5 minutes or until light and fluffy, scraping down the sides as needed.
- Add eggs and vanilla and mix until just combined.
- Continue mixing and add half of the dry ingredients, followed by the sour cream, then the remaining dry ingredients, and finally the milk. Mix until just combined.
- Pour batter into baking dish, layer on the fruit, and top with streusel.
- Bake for 45-55 minutes or until golden brown and a toothpick inserted in the middle comes out without any raw batter. Allow to cool for at least five minutes prior to serving. Serve warm or cold.
Storage: Cover and refrigerate for up to one week.
Nutrition Information:
Yield: 12 Serving Size: 1Amount Per Serving: Calories: 487Total Fat: 21gSaturated Fat: 12gTrans Fat: 1gUnsaturated Fat: 7gCholesterol: 100mgSodium: 377mgCarbohydrates: 70gFiber: 2gSugar: 40gProtein: 6g
The nutritional information provided is computer generated. It is only an estimate and intended for informational purposes only. Nutrition details may vary depending on various factors such as origin, freshness of ingredients, etc
Moop Brown
Monday 17th of January 2022
I've been wanting to try some more baking recipes lately and this one looks really tasty and flavorful.
Heidy
Sunday 16th of January 2022
This Blueberry Rhubarb Buckle with Cardamom Streusel was so wonderful. I cannot wait to make it again! Great recipe with excellent instructions. Have a great day!
Natalie
Sunday 16th of January 2022
Beautiful dessert. Perfect for lazy weekend afternoons with a cup of coffee. Oh, I can't wait to give this a try. Thank you for sharing this lovely recipe.
Ksenia
Sunday 16th of January 2022
What a gorgeous flavour combination! I think you’re so rational, pairing rhubarb with l blueberries and cardamom. I can’t wait to make this once rhubarb appears around here
Tristin
Saturday 15th of January 2022
Is it wrong that we ate this for breakfast? The flavors in this Blueberry Buckle were incredible. Such a great combination with the rhubarb, blueberry and cardamom. Making again soon!!