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Rhubarb streusel cake balances tart rhubarb with a sweet brown sugar streusel topping. This tender rhubarb cake is perfect for brunch, an afternoon snack, or a simple yet delicious summertime dessert.
The first time I had rhubarb was about 15 (15!!) years ago, when I first shared this rhubarb cake recipe.Â
(It’s crazy to me that I’ve been sharing recipes here for that long!)
I found some stunning rhubarb at the farmers’ market and decided it was time to put it to good use and give it a try.
I got home and began searching for inspiration and found this lovely cake recipe. You know I’m a sucker for anything with a streusel topping!
I thoroughly enjoyed the flavor of the rhubarb baked into this gorgeous cake, and now I’m totally a fan.Â
I have tweaked this recipe over the years and made it even better, but it’s still one of my favorite ways to use fresh late-spring/early-summer rhubarb.
What is rhubarb?
Rhubarb is a perennial vegetable that grows between late spring and early summer, usually April through June.
Yes, even though it’s usually treated like a fruit when we cook and bake with it, it’s actually a vegetable!
The rhubarb plant has thick pinkish-green stalks and large leaves. The leaves are inedible, so make sure you discard those—the stalks are what you want.
Rhubarb is very tart and when it is raw, it is crisp and a bit stringy. You can eat it when it’s raw, but it’s so tart that it doesn’t taste very good. (I am definitely not a fan of raw rhubarb!)
Because it’s so tart, rhubarb is usually served cooked into desserts or other sweet recipes.Â
Rhubarb has a pretty short growing season, so grab it when you find it! Buy some extra to freeze for later, too. You can also find frozen rhubarb at some grocery stores, so you can enjoy this delicious rhubarb cake year-round.
How to make this rhubarb cake
This rhubarb streusel cake could definitely be considered a coffee cake recipe.
The base is a simple, tender cake with a light crumb. The cake itself has plenty of chopped rhubarb in it, and the whole thing gets topped with a brown sugar streusel for extra flavor, sweetness, and crunchy texture.
This is the kind of cake that you can enjoy for breakfast or brunch with a cup of coffee, for an afternoon snack as a pick-me-up with an iced shaken espresso, or for a delicious dessert with a dollop of whipped cream or a scoop of vanilla ice cream.
Ingredients you’ll need
To make this rhubarb cake, you will need:
- 2 tablespoons softened unsalted butter
- 1 cup granulated sugar
- 1 large egg
- 1 teaspoon pure vanilla extract
- 2 cups all-purpose flour
- 1 teaspoon baking powder
- 1/2 teaspoon baking soda
- 1/2 teaspoon fine sea salt
- 1 cup buttermilk
- 3 cups chopped fresh or frozen rhubarb
Yes, the cake itself only has 2 tablespoons of butter in it, but don’t worry! It’s still going to be really tender and flavorful thanks to using buttermilk.
But you forgot to buy buttermilk, don’t stress. You can make a 2-ingredient buttermilk substitute to use instead.
You can use fresh or frozen chopped rhubarb in this cake. If you are using frozen rhubarb, do not thaw it before adding it to the cake.
And of course, make sure you know how to measure flour correctly before you get started! Nailing this step will help your cake turn out perfect every time.
The thing that really makes this cake extra amazing is the streusel topping. For that, you will need:
- ½ cup all-purpose flour
- ½ cup lightly packed light brown sugar
- 4 tablespoons melted unsalted butter
If you are out of brown sugar, make a brown sugar substitute to use in the streusel. If yours hardened in the pantry, check out my tips for how to soften brown sugar.
Making this cake
To make the rhubarb cake batter, use an electric mixer to beat the butter, sugar, egg, and vanilla until the mixture is well combined and light in color.
In a separate mixing bowl, whisk together the flour, baking powder, baking soda, and salt.
With the mixer on low, add half of the dry ingredients to the sugar mixture, mixing until just combined. Add all of the buttermilk, mixing until just combined, then finish with the rest of the dry ingredients.
Make sure to scrape the sides of the bowl with a spatula as needed.
Fold in the chopped rhubarb, then spread the batter into a greased 9×9-inch cake pan.
To make the streusel, use a fork to mix together the streusel ingredients until clumps form. Sprinkle the streusel mixture evenly over the top of the cake.
Bake the rhubarb cake at 350°F for 60-70 minutes; the cake is done when a toothpick inserted into the center comes out clean.
Rhubarb cake storage and freezing
Store this rhubarb cake in an airtight container at room temperature for up to 3 days.
If you’d like to freeze leftover slices of the cake, wrap them in plastic wrap and place them in a zip-top freezer bag or airtight container. Freeze for up to a month.
To thaw, let a slice of the cake rest at room temperature for a couple of hours or unwrap it and microwave it for about 60 seconds to thaw it and warm it through.
More delicious rhubarb recipes
If you have also discovered that you love rhubarb, you’re in luck because there are so many ways to enjoy it!
Rhubarb is often paired up with strawberries for a tart-sweet combo. Some great options include gluten-free strawberry rhubarb crumble, a sparkling strawberry rhubarb cocktail, or strawberry rhubarb crumb bars.
Rhubarb pairs really well with other fruits too, though, such as blueberries in a blueberry rhubarb crisp!
And as you’ve seen from this recipe, it’s also fantastic on its own. Try it in rhubarb pie, rhubarb margaritas, or make a rhubarb syrup to use in all kinds of delicious ways.
For the streusel topping:
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Preheat the oven to 350°F. Spray (1) 9×9-inch cake pan with nonstick spray. Set aside.
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In a large bowl with an electric mixer, beat the butter, sugar, egg, and vanilla on medium speed until light in color and well combined.
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In a separate bowl, whisk together the flour, baking powder, baking soda, and salt. With the mixer on low, add half of the flour mixture to the sugar mixture, mixing until just combined. Add all of the buttermilk, mixing until just combined, then finish with the rest of the flour mixture. Mix until just combined, scraping the sides of the bowl with a rubber spatula as needed.
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Fold in the chopped rhubarb.
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Spread the batter into the prepared cake pan.
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In a small bowl, mix together the streusel ingredients with a fork until clumps form. Sprinkle the streusel evenly over the top of the cake.
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Bake for 60-70 minutes or until a toothpick or cake tester inserted in the center of the cake comes out clean.
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Allow cake to cool before serving.
For sauce, melt ½ cup unsalted butter in a saucepan. Add ¾ cup granulated sugar, ½ cup evaporated milk and ½ of a scraped vanilla bean (or 1 teaspoon vanilla bean paste). Bring to a boil; cook and stir for 2-3 minutes or until thickened. Remove from the heat. Serve with cake.
Adapted from allrecipes.
Serving: 1slice, Calories: 359kcal, Carbohydrates: 64g, Protein: 6g, Fat: 9g, Saturated Fat: 6g, Polyunsaturated Fat: 1g, Monounsaturated Fat: 2g, Trans Fat: 0.3g, Cholesterol: 41mg, Sodium: 279mg, Potassium: 217mg, Fiber: 2g, Sugar: 36g, Vitamin A: 346IU, Vitamin C: 3mg, Calcium: 112mg, Iron: 2mg
Nutrition information is automatically calculated, so should only be used as an approximation.
