Sourdough Discard Crumb Cake

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

a sourdough discard crumb cake on a cutting board with a slice removed

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:

a bowl with sourdough discard whisked with eggs
Whisk the sourdough discard with the eggs and vanilla.
two side by side photos showing how to make crumb topping
Mix the butter into the brown sugar until it looks like wet sand. The topping should hold together in large clumps.
two photos showing how to assemble sourdough crumb cake
Spread the batter into the prepared pan, then crumble the topping evenly over the batter.
two photos showing sourdough crumb cake before and after baking
Bake the cake until a toothpick inserted in the middle comes out clean. Use the parchment to transfer the cake to a rack to finish cooling.
a stack of sourdough discard crumb cake slices on a cake stand
a slice of sourdough crumb cake on a black plate

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.

a slice of sourdough crumb cake on a plate
Print Recipe
4.65 from 14 reviews

Sourdough Crumb Cake

Soft buttermilk cake enhanced with sourdough discard & crowned with brown sugar crumb topping.
Prep Time30 minutes
Bake Time45 minutes
Total Time1 hour 15 minutes
16 servings
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Crumb Topping

  • 6 ¾ oz cake flour (1 ½ cups, see note)
  • 5 ¼ oz brown sugar (⅔ cup)
  • ¼ teaspoon salt
  • 2 teaspoons cinnamon
  • 4 oz unsalted butter (cool room temperature)

Cake Batter

  • 8 oz sourdough discard (1 cup)
  • 1 large egg
  • 1 large yolk
  • 1 tablespoon vanilla extract
  • 6 ¾ oz cake flour (1 ½ cups)
  • 6 oz granulated sugar (¾ cup)
  • 1 ½ teaspoons baking powder
  • ¼ teaspoon salt
  • 4 oz unsalted butter (room temperature)
  • 4 oz buttermilk (½ cup, room temperature)


  • 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 6 ¾ oz cake flour, 5 ¼ oz brown sugar, ¼ teaspoon salt and 2 teaspoons 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 4 oz unsalted 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.


  • In a small bowl, whisk 8 oz sourdough discard, 1 large egg, 1 large yolk and 1 tablespoon vanilla extract in a small bowl and set aside.
  • Sift 6 ¾ oz cake flour, 6 oz granulated sugar, 1 ½ teaspoons baking powder and ¼ teaspoon salt into the bowl of a stand mixer or into a large mixing bowl. With the mixer running on low speed, add 4 oz unsalted butter and 4 oz 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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If measuring the flour by volume use the “dip & sweep” method. That is, dip the measuring cup into the flour bin, overfill it, then sweep away the excess.


Serving: 1slice | Calories: 292kcal | Carbohydrates: 41g | Protein: 4g | Fat: 13g | Saturated Fat: 8g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 3g | Trans Fat: 0.5g | Cholesterol: 54mg | Sodium: 129mg | Potassium: 57mg | Fiber: 1g | Sugar: 20g | Vitamin A: 398IU | Vitamin C: 0.01mg | Calcium: 51mg | Iron: 0.4mg
Have you tried this recipe?Mention @eileen.bakingsense or tag #bakingsense!

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Recipe Rating


  1. 5 stars
    Just came out of the oven with this and I know it’s gonna be delicious . . . I put Blueberries in it so I’m having to wait for the 20 minute cooling in the pan and then a little longer to make sure it doesn’t crumble. Can’t thank you enough for all the work and instruction you’ve put into all of these recipes for us Eileen . . . you are truly a talented and gracious lady.

  2. 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.


    1. 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.

  3. 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.

    1. 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.

  4. 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!

  5. 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!

  6. This recipe looks PERFECT as I have starter, buttermilk that I don’t know what to do with, and cake flour. Will make this tomorrow for my bday!

  7. 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

    1. 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.

  8. 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!

  9. 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.

    1. 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…….