Sourdough Discard Crumb Cake is a soft buttermilk cake enhanced with sourdough discard & crowned with lots of brown sugar crumb topping.

I absolutely love a good crumb cake. What makes a good crumb cake?
Well, first of all, I think there needs to be almost as much crumb as cake. Second of all, that cake should be super tender and moist.
You know what helps make a cake super tender and moist? Sourdough discard!
If you don’t have one, you can learn How to Make a Sourdough Starter. Then I can show you how to Feed and Maintain Sourdough Starter or How to Keep a Small Sourdough Starter.
If you don’t have a starter yet, you can make this fabulous Blueberry Crumb Cake in the meantime.
If you’ve got your discard ready to go, let’s get started….
How to use your discard to make a great Sourdough Crumb Cake:
- To make a great crumb topping the butter should be at room temperature, a bit flexible but still a little firm. If the butter is too soft the crumb will be too crunchy. If the butter is too cold it won’t mix into the sugar properly and you’ll end up with lumps of butter.
- A ripe unfed starter adds more tangy flavor to the cake. A recently fed starter gives a more mild flavor. I generally use mine after about 1 week without a feeding (kept in the refrigerator).
- When you’re ready to mix the batter, the discard should be at room temperature just like all the other ingredients.
- Once you add the egg/discard mixture, stir just until combined. Over stirring after the liquid is added will develop gluten and toughen the cake.
- You can fold 2 cups of blueberries or diced apples into the batter.
- The cake keeps for several days at room temperature.
- Individual slices can be wrapped and frozen for up to 3 months.
Scroll through the process photos to see how to make Sourdough Crumb Cake:






Since you’ve got your starter fed, peruse the entire list of My Best Sourdough Recipes. Have fun!
I know you hate to throw away that sourdough discard. Check out these recipes that use sourdough discard.
If you love this recipe as much as I do, I’d really appreciate a 5-star review.

Sourdough Crumb Cake
Soft buttermilk cake enhanced with sourdough discard & crowned with brown sugar crumb topping.
Ingredients
Crumb Topping
- 1 1/2 cups (6.75 oz, 189g) cake flour
- 2/3 cup (6 oz, 168g) light brown sugar
- 1/4 teaspoon salt
- 2 teaspoons cinnamon
- 1 stick (4 oz, 112g) unsalted butter, room temperature
Cake Batter
- 1 cup (8 oz, 224g) sourdough discard
- 1 large egg plus 1 yolk
- 1 tablespoon vanilla extract
- 1 1/2 cups (6.75 oz, 189g) cake flour
- 3/4 cup (6 oz, 168g) granulated sugar
- 1 1/2 teaspoons baking powder
- 1/4 teaspoon salt
- 1 stick (4 oz, 112g) butter, room temperature
- 1/2 cup (4 oz, 120ml) buttermilk
Instructions
- Preheat the oven to 350°F. Butter and flour a 9" square cake pan. Cut an 8"x16" piece of parchment paper and line the pan in one direction, leaving a short overhang on each side.
Crumb Topping
- Combine the flour, brown sugar, salt, and cinnamon into the bowl of a stand mixer or into a large mixing bowl. Mix on low speed until completely combined. With the mixer running, add the butter in chunks and continue to mix until the topping looks like wet sand. Remove from the mixer and transfer to a small bowl by squeezing handfuls to create large clumps. Set aside while you mix the batter.
Batter
- In a small bowl, whisk the sourdough discard with the egg, yolk, and vanilla in a small bowl and set aside.
- Sift the flour, sugar, baking powder and salt into the bowl of a stand mixer or into a large mixing bowl. With the mixer running on low speed, add the butter and the buttermilk. Mix until completely combined. Scrape the bowl and beater. Mix on medium speed for 2-3 minutes to lighten the batter.
- Scrape the bowl and add the sourdough discard mixture in two batches, scraping between additions. Mix just until combined. At this point you can fold in 2 cups of blueberries or diced apples if you'd like. Spread the batter into the prepared pan.
- Sprinkle on the crumb topping, breaking it into marble sized clumps as you scatter it evenly over the cake batter.
- Bake until a toothpick inserted in the center comes out clean, about 45-50 minutes. Cool 10 minutes in the pan (30 minutes if you put fruit into the cake). Use the parchment to carefully lift the cake out of the pan.
- Cool completely on a wire rack
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Sasha
Is cake flour self raising flour for this recipe?
Ps. I love you recipes especially the sour dough, so easy to understand and follow!! And delicious. Thank you
Eileen Gray
Thanks, Sasha. Cake flour is not self rising flour. Cake flour is a low-protein flour which makes softer cakes. If you are using self rising flour you’ll need to eliminate the salt and baking powder in the recipe since self rising flour already has those ingredients in them. Also, the cake may have a slightly different texture since SR flour has a slightly higher protein content than cake flour. I think you should still get a good result, though.
Christi
The cake looks delightful! A bit dense but definitely not heavy. It looks to have a very fine crumb which, on my opinion, is the very best way to judge a cake aside from actual flavor! I’ve never been much of a sourdough baker, but this one intrigued me enough I’m gonna have to try my hand at it. Thanks for sharing such an exciting new recipe!
Eileen Gray
Actually, the cake is not at all dense. It does have a fine crumb, but it melts in your mouth.
Long
Delicious…but the baking time seems offI love the flavor, and I feel the amount of crumb topping is decadent and delicous. I wouldn’t change it.
Eileen Gray
Did you actually bake the recipe or are you just guessing that the baking time if off? Baking times are always just a guideline. If you did bake the cake and ended up with a different baking time there are a number of factors that can affect the actual baking time. If your oven temp is not accurate that can change the baking time. If your batter is very cold or very warm it can change the baking time. A lighter or darker color or weight pan can affect the baking time…….