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You’ll love this old-fashioned rhubarb cake recipe with a tender crumb, and tart rhubarb in every bite. Buttermilk makes the cake tender and moist, while a spiced brown sugar cinnamon streusel topping makes it impossible to pass up a slice.
Rhubarb is here for a good time, not a long time, and this rhubarb cake is one of my favorite ways to put it to use!
Yes, rhubarb is the star here, but don’t worry—this cake is not at all sour. Brown sugar in the cake and a streusel topping temper its tartness without drowning out its flavor.
Rhubarb is often paired with strawberries or blueberries to balance that pucker (see strawberry rhubarb jam, strawberry rhubarb crisp, or blueberry rhubarb jam), but it also deserves to take center stage once in a while. And that’s exactly what you get in this rhubarb dump cake recipe.
Important Ingredient Notes
A complete ingredient list is in the recipe card below, but here are a few highlights:
- Brown sugar – I recommend light brown sugar for the streusel, but dark brown sugar will do if that’s what you have on hand. It has a stronger molasses flavor. Out of brown sugar? Check out our tutorial on how to make brown sugar.
- Buttermilk – If you don’t have buttermilk on hand, you can add a tablespoon of lemon juice or vinegar to a liquid measuring cup, then fill it with milk (preferably whole milk) until it reaches the 1 cup mark. Whisk it well and let it sit for 5 minutes before using. If you do use buttermilk, save leftovers with our how to freeze buttermilk tutorial.
- Rhubarb – Look for stalks that are firm and fairly thin. Stalks that are thick tend to be tough. As in they are hard to chew, not that they’ll steal your hub cabs on a moonless night.
PRO TIPS/RECIPE NOTES
- Spoon the flour into the measuring cup rather than scooping it. When you scoop flour out of the bag or container, it compacts it, which means you end up using more than you really need.
- Don’t forget to sift the flour! This helps give the rhubarb cake a light, airy texture.
- And don’t forget to soften the butter and let the egg come to room temperature either. This allows them to mix more evenly into the cake batter and gives them the ability to hold more air when beaten, which also contributes to the light texture of this cake.
- Take care not to overmix the batter. It’s always better to have a few streaks of flour than mix too much, which can make your cake dense.
Rhubarb Coffee Cake Recipe
Ingredients
Streusel Topping
- 1/2 cup sugar
- 1/3 cup brown sugar, packed
- 2/3 cup all-purpose flour
- 1 1/2 tsp cinnamon
- 6 tbsp butter, melted {salted or unsalted is fine}
Cake Ingredients
- 2 cups all-purpose flour, sifted
- 1 tsp baking soda
- 1/2 tsp baking powder
- 1/2 tsp salt
- 1 cup brown sugar, packed
- 1/2 cup butter {room temperature}
- 1 egg {room temperature}
- 1 tsp vanilla
- 1 cup buttermilk
- 2 cups rhubarb {finely chopped}{~2 medium stalks}
Instructions
- Make the streusel topping: In a medium mixing bowl combine sugars, all-purpose flour, and cinnamon.1/2 cup sugar, 1/3 cup brown sugar, packed, 2/3 cup all-purpose flour, 1 1/2 tsp cinnamon
- Drizzle in the melted butter. Mix with a fork or a pastry cutter until well combined. Place bowl in the fridge.6 tbsp butter, melted
- Preheat oven to 350˚F.
- Butter a 9×13 baking pan.
- In a small bowl mix together flour, baking soda, baking powder, and salt. Mix well.2 cups all-purpose flour, sifted, 1 tsp baking soda, 1/2 tsp baking powder, 1/2 tsp salt
- In a stand mixer beat brown sugar and butter together on medium-high until light and fluffy.1 cup brown sugar, packed, 1/2 cup butter
- Add egg and vanilla extract to the butter/sugar mixture, and mix just until combined.1 egg, 1 tsp vanilla
- Add the flour mixture and mix until just combined.
- With the mixer running on low, add in the buttermilk and mix until just combined. Do not overmix.1 cup buttermilk
- Add in the rhubarb and mix until thoroughly combined. Pour the mixture into the buttered pan.2 cups rhubarb
- Bake the cake for 20 minutes at 350˚F, then sprinkle the topping on top of the cake batter and bake for another 15-25 minutes or until the middle of a toothpick inserted into the middle comes out clean.
Notes
- If you’re very sensitive to tart flavors, you can increase the sugar in the cake by 1/2 cup without impacting the overall texture.
- The cake batter will have the texture of buttercream frosting before it is baked.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
This is a lovely cake and really makes the rhubarb shine. I love the generous crunchy streusel and the cake texture is amazing. Great recipe!
Very moist, loved the crumb topping. Sweetness was spot on.
I love hearing that, Kim!
I no longer “tell stories” in my blog posts, but I found the base recipe for this cake in my mom’s old Tupperware recipe holder. I adapted it a bit, but it’s still mostly hers. She passed away in 2017, so I love that food connects us. And I love that I get to share it with others.