This delicious rhubarb streusel cake is sweet and tangy, super moist, tender, and flavorful and will have you coming back for seconds!
My husband has always claimed he doesn’t care much for cake or rhubarb but he really enjoys diving into this Rhubarb Streusel Cake. It isn’t overly sweet and the tanginess of the rhubarb provides a nice contrast and balance. So if you fall into the camp of someone who doesn’t like rhubarb, this cake may change your mind!
Rhubarb goes back a long way. Â It has been used in Chinese medicine for thousands of years. Â Over the centuries the rhubarb trade increased and in Medieval Europe its value exceeded that of fine spices such as cinnamon and saffron! Rhubarb entered the U.S. in the 1820’s and has been enjoyed in the popular form of pies, crumbles, compote, and preserves ever since.
By the way, did you know that rhubarb is technically a vegetable? Yet interestingly it was designated as a fruit in the U.S. in a 1947 court ruling for the purposes of regulations and duties.
What’s interesting is that even though rhubarb is a vegetable, it’s generally only used in sweet dishes as a fruit. Yet tomatoes, which are technically fruits, are generally only used in savory dishes as vegetables. Have any of you ever made or seen rhubarb served as a vegetable or tomatoes served as fruits?  Chime in if you have!
One last interest tidbit about rhubarb from Wiki: Â “In British theater and early radio drama, the words “rhubarb, rhubarb” were repeated for the effect of unintelligible conversation in the background.” Â Pretty amusing, huh?
Go grab some rhubarb while it’s still available and make this fantabulous Rhubarb Buttermilk Streusel Cake! Â A tender and moist crumb with a delightful buttery streusel topping (which, incidentally, comes from the German verb “streuen,” which means to sprinkle or scatter) . Â This cake is truly lovely and it’s easy to make. Â Serve it up with some ice cream and you’re all set.
Rhubarb Streusel Cake Recipe
Let’s get started!
Cream the butter and sugar in large mixing bowl with an electric mixer.
Add the eggs and vanilla extract. Beat until combined.
In a separate bowl, combine the flour, baking powder, baking soda, and salt. Using a rubber spatula, fold in the flour, alternating the flour and buttermilk.
Be careful not to over-stir. Â Some lumps of flour will remain, and that’s okay.
Wash the rhubarb.  Peel off the outer skin if it’s too tough. Dice the rhubarb and add it to the batter. Fold the rhubarb into the batter.
Spread the batter into a greased 8×8 inch square baking pan. Â I use the hand-forged aluminum pan by Magic Line, made in the USA. Â Love it!
To make the streusel, combine the butter, sugar and flour in a bowl. Crumb the mixture between your fingers.
Evenly crumble the streusel over the batter.
Bake in an oven preheated to 350 degrees F for 35-45 minutes or until the streusel is a light golden brown in places and a toothpick inserted into the middle of the cake comes out clean.
Let the cake cool before slicing it.
Serve with some ice cream and you’re all set! Â Enjoy!
For more delicious rhubarb treats be sure to try our:

Rhubarb Streusel Cake
Ingredients
- 1/4 cup unsalted butter at room temperature
- 1 cup sugar
- 1 teaspoon vanilla extract
- 1 large egg
- 2 cups all-purpose flour
- 1 teaspoon baking powder
- 1/2 teaspoon baking soda
- 1/2 teaspoon salt
- 1 cup buttermilk
- 2 1/2 cups rhubarb diced
- For the streusel topping:
- 1/4 cup butter melted
- 1/2 cup flour
- 1/2 cup sugar
Instructions
- Preheat the oven to 350 degrees F. Grease a 8x8 inch square baking pan.
- Cream the butter and sugar in a large mixing bowl. Add the vanilla extract and egg and beat until combined.In a small bowl, combine the flour with the baking powder, baking soda, and salt.Using a rubber spatula, fold the flour mixture into the wet mixture, alternating with the buttermilk. Be careful not to over-stir. Some flour lumps will remain and that is okay. Stir in the rhubarb.Spoon the batter into the greased baking pan.
- To make the streusel topping, combine all the ingredients and crumble with your fingers. Evenly sprinkle the streusel topping over the cake batter. Bake the cake for 35-45 minutes or until a toothpick inserted into the center of the cake comes out clean.Let the cake cool before cutting into squares. Serve with ice cream, whipped cream, or vanilla custard.
Nutrition
Beth Ruest says
This is a great recipe. I have been making this for several years now and have had many requests for the recipe. Even my son who doesn’t eat cake ( he prefers pies) has a big piece when I serve this. Thanks for such a wonderful recipe that has become a fan favourite in our large family.
Kimberly Killebrew says
I’m beyond thrilled to hear that, Beth, thanks so much for letting me know! <3
Kay says
Please note that although the recipe states to cream the butter and sugar until pale and fluffy this is impossible due to ratio of sugar and butter used so instead should state beat well as I thought I was doing something wrong and started over. Otherwise, cake turned out really well, very moist and I’d make it again.
Kimberly Killebrew says
I’m so glad you enjoyed it, Kay, and thank you for the feedback! I looked and noticed that the written instructions in the blog post did not mention beating the butter and sugar until pale and fluffy but somehow that verbiage was added to the recipe card. Thanks for catching that, I’ve updated it.
wendy says
Do you think it would be possible to use apples instead of rhubarb in this recipe please?
Kimberly Killebrew says
Absolutely, Wendy! Happy baking!
Bieny Pryor says
This is a delicious way to use rhubarb. I will use a bit more rhubarb next time I make it. Do you know if it freezes well? I’m worried the rhubarb will get watery.
Kimberly Killebrew says
Hi Bieny, I haven’t tried freezing it but I’ve had some readers report that they did so successfully – just took the cake out of the freezer and let it thaw at room temperature.