My version of a coffee cake, this rhubarb crumb cake is studded with jammy bits of tart rhubarb and topped with a cinnamon-laced brown sugar streusel. A favorite summer bake for those lazy mornings.

This pretty rhubarb crumb cake is so lovely on the summer brunch table, or enjoyed outside on a sunny morning with a hot cup of coffee. There's plenty of rhubarb here to celebrate this seasonal beauty, and it's balanced by a crisp and crumbly sweet topping, so it's not toooo tart. A nice morning alternative to a more dessert-y upside-down rhubarb cake.
Make sure to check out my easy rhubarb recipes post for lots more rhubarb recipes, and see my gluten free rhubarb crumb cake post for a gluten-free version of this recipe!
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Why I Love This Humble Cake
- It's not fussy. Like my gluten free coffee cake or gluten free blueberry coffee cake recipes, this rhubarb crumb cake is meant to be rustic! No need to fancy it up with anything; it's best enjoyed with your favorite morning beverage.
- So tender. No crumbly or dry gluten-free cake here! The cake itself is soft and tender, punctuated by the tart pockets of rhubarb, and the crumb topping lends a bit of crunch without being too much.
- It's the rhubarb for me. It's no secret that I dearly love rhubarb, and finding more ways to use it always gives me a little thrill. Think beyond rhubarb compote or rhubarb jam and make this cake, which delivers lots of that unique flavor in every bite.

Ingredients Needed
Here's what you'll need for this crumb cake. Make sure to scroll down to my recipe card at the bottom of this post for the full ingredient amounts and instructions!
- Butter - Unsalted butter is used in the topping and the cake.
- Flour - I like using whole wheat flour in this cake for a dose of whole grain goodness. You can use whole wheat flour, whole wheat pastry flour, or spelt flour. If you wish, all-purpose flour is also fine.
- Brown sugar - Light or dark brown sugar is fine.
- Ground cinnamon - Or substitute ground ginger.
- Baking powder
- Salt - Fine sea salt or table salt.
- Granulated sugar
- Egg - A large or medium egg is best.
- Vanilla - Use pure vanilla extract or vanilla bean paste.
- Milk - I prefer whole milk for richness, and 2% milk is also fine.
- Rhubarb - Choose firm rhubarb with no brown spots. Frozen rhubarb can be used if needed.
Variations
- Add strawberries - Make this into a strawberry rhubarb crumb cake - like in my gluten free strawberry rhubarb cake, these two were meant to be together. Swap ½ cup chopped rhubarb for ½ cup chopped strawberries.
- Orange zest - Rhubarb also loves orange. Zest 1 orange into the sugar, rub it in with your hands to release the oils, then proceed with the recipe.
- Almonds - Sprinkle a layer of sliced almonds (about ½ cup) over the top of the batter before adding the crumble for a bit of crunch.

Step-by-Step Instructions
Here's an overview in photos of how to make a rhubarb crumb cake:

1. Make topping: Mix the topping ingredients, then chill in the fridge.

2. Combine dry ingredients: In a small bowl, whisk together the flour, baking powder, and salt.

3. Cream butter: In a separate bowl, cream the butter and sugar, then add the egg.

4. Combine: Add the flour mix and fold in the rhubarb. Place batter in a lined 8x8-inch pan.

5. Add topping: Sprinkle the topping over the batter.

6. Bake: Place in a 350F oven and bake for about 40 minutes.

Tips & Recipe Notes
- Keep the topping in the fridge. After assembling the crumb topping, keep it in the fridge so it firms up a bit while you make the cake. You may need to break up the topping with your hands before sprinkling it over the cake.
- Can I use frozen rhubarb? Yes - frozen rhubarb works great in this recipe. No need to defrost it before stirring it into the batter.
- Use all brown sugar. For a deeper note of caramel sweetness, swap the granulated sugar for brown sugar in the batter.
- Optional serving suggestions: With whipped cream, a drizzle of salted caramel sauce, a scoop of vanilla ice cream, or it's just perfect as-is!
Proper Storage
- Counter - Cover the pan of cake tightly with foil, or transfer it to an airtight container, and store on the counter for up to 3 days.
- Fridge - Transfer the cake to the fridge and store it for up to 1 week.
- Freezer - Wrap the cake in foil, then freeze for up to 2 months. Thaw in the fridge before serving.
More Rhubarb Cake Recipes
Happy baking! If you make this rhubarb crumb cake recipe, I'd love to know. Please leave a comment below, reach out with any questions, and tag me on Instagram @Cucina Nicolina ❤️
Recipe

Rhubarb Crumb Cake
Ingredients
Topping
- 6 tablespoons unsalted butter melted
- 1 cup whole wheat pastry flour , or all-purpose flour
- ½ cup brown sugar
- 1 teaspoon ground cinnamon
Cake
- 1 ½ cups whole wheat pastry flour , or all-purpose flour
- 1 ½ teaspoon baking powder
- ½ teaspoon fine sea salt
- 4 tablespoons unsalted butter room temperature
- ¾ cup granulated sugar
- 1 large egg
- 2 teaspoons pure vanilla extract
- ⅔ cup whole milk
- 1 ½ cups rhubarb cut into ½ inch pieces
Instructions
- Preheat oven to 350℉. Butter an 8-inch square baking pan and line the bottom with parchment paper.
- Make the topping: In a medium bowl, stir together 6 tablespoons unsalted butter, 1 cup whole wheat pastry flour, ½ cup brown sugar, and 1 teaspoon ground cinnamon until combined. Place in the fridge so it can firm up a bit.
- Make the cake. In a medium bowl, whisk together the 1 ½ cups whole wheat pastry flour, 1 ½ teaspoon baking powder, and ½ teaspoon fine sea salt. In a large bowl with an electrix mixer on medium speed, cream the 4 tablespoons unsalted butter and ¾ cup granulated sugar until fluffy, then beat in the 1 large egg and 2 teaspoons pure vanilla extract.
- Add the flour mixture to the creamed mixture in 2 additions, alternating with the ⅔ cup whole milk. Beat well to combine. Fold in the 1 ½ cups rhubarb.
- Spread the batter in an even layer into the prepared pan. Take the topping out of the fridge; it will be solidified. Using your hands, break it up and crumble it evenly over the top of the batter.
- Place in the oven and bake for about 40 minutes, until a tester inserted in the center comes out mostly clean. Let cool in the pan set on a wire rack to room temperature.
Notes
- Keep the topping in the fridge. After assembling the crumb topping, keep it in the fridge so it firms up a bit while you make the cake. You may need to break up the topping with your hands before sprinkling it over the cake.
- Can I use frozen rhubarb? Yes - frozen rhubarb works great in this recipe. No need to defrost it before stirring it into the batter.
- Use all brown sugar. For a deeper note of caramel sweetness, swap the granulated sugar for brown sugar in the batter.
- Optional serving suggestions: With whipped cream, a drizzle of salted caramel sauce, a scoop of vanilla ice cream, or it's just perfect as-is!









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