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 already have one, I can show you how to make a sourdough starter and how to feed a 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 sourdough discard to make a great 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 this recipe:






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 (5.25 oz, 150g) 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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Michele
Monday 22nd of August 2022
I’ve tried this and it’s delicious. But I noticed it seemed overly sweet. I always weigh ingredients in grams when baking, and when I went back and looked at the recipe, I think your weights on the sugar may be off.
Most online sources indicate 2/3 cup brown sugar weighs 133 grams. You have the 2/3 cup brown sugar at 168 grams. Also, again from online sources, 3/4 cup granulated sugar is 150 grams and you have it as 168.
If I had been using my measuring cups, I’m thinking it wouldn’t have been so sweet.
Not meaning to be critical - as I said the cake is delicious and a great way to use a large amount of discard. But next time I’m cutting down on the sugar.
Thanks!
Eileen Gray
Monday 22nd of August 2022
I did have the weight of the brown sugar wrong as I changed the amount and didn't change the weight. But, in general, regarding weighing dry baking ingredients there is not an absolutely "correct" weight/cup conversion. The amount of sugar or flour in a measuring cup is dependent on how the cup is filled. For example, I assume 8oz per cup of sugar and others may assume something a little less like 7-7.5 oz per cup. If you dip a cup into sugar and weigh it several times you'll see that it will vary a bit. So for all my recipes I set a standard weight/cup based on how I do it. I always weight my ingredients so weighing ingredients will give you the best outcome for my recipes. I give the cup conversions because many US bakers don't use a scale for baking. As far as the sweetness of the cake, that's a personal preference and you can feel free to reduce the sugar to your liking.
Robin
Saturday 21st of May 2022
This looks great! Can I make the batter the day before and refrigerate it overnight? I’d like to bake it in the morning but want to do all the mixing and assembly the night before. I’d put the crumb topping in a separate container and add it before baking.
Eileen Gray
Saturday 21st of May 2022
Chances are the discard (being fed from the flour in the batter) would activate the start to rise. Personally, I would prep the pan, make the topping and measure out all the cake ingredients. Mixing the cake batter would take just a few minutes in the morning if everything is measured out already.
Kristel
Saturday 12th of February 2022
This was amazing! Made it for Christmas, and there was just 1 piece left (which I hid from my family). Can't wait to make it again! I have loved every recipe I've tried from this site. Thanks for such great recipes!
Denise Severson
Sunday 11th of July 2021
Kitchen is def passing the "aroma test" while baking; looking forward to the final test: tasting. Thank you for another great recipe to actually use discard instead of throwing it away!
Nancy Corazzi
Sunday 30th of May 2021
Delicious, and a wonderful moist texture. So much better than Entemmanns!