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This sourdough chocolate cake is rich, moist, and unapologetically fudgy. Exactly what a good chocolate cake should be. It turns that leftover sourdough discard into something worth celebrating, no tangy aftertaste, no weird texture, just a deep, chocolatey crumb that stays soft for days.
And that chocolate buttercream? Smooth, fluffy, and just the right amount of decadent. You don’t need to be a sourdough pro to pull this off, just a mixing bowl and a craving for real cake.
I adapted my recipe from my chocolate cake with cream cheese frosting. A longtime favorite around here. The original is rich, tender, and foolproof, so it made the perfect starting point for a sourdough version.
Here is Why This Sourdough Chocolate Cake Recipe Works
- Uses up that sourdough discard without making everything taste like a science experiment, just rich, chocolatey cake goodness.
- No mixer required for the batter, just a bowl, a whisk, and a little ambition.
- Ultra-moist texture thanks to the oil and sourdough discard.
- Freezes well, so you can stash a slice (or three) for future chocolate emergencies.
Recipe Tips
Use fresh-ish discard: It doesn’t need to be bubbly, but skip the stuff that’s been forgotten in the back of the fridge for weeks.
Bloom the cocoa: Whisking it with hot coffee (or hot water) deepens the chocolate flavor, don’t skip this step.
Don’t panic over thin batter: It’s supposed to look pourable but it bakes up just fine.
Cool completely before frosting: Buttercream + warm cake = a sad, melty mess.
Sift the dry ingredients right into the bowl to keep the batter lump-free and evenly mixed.
Use room temp ingredients (eggs, milk, discard) so everything blends smoothly.
Test for doneness early: Ovens vary, and this cake can go from perfect to overbaked fast. A toothpick should come out with a few moist crumbs, not wet batter.
Got more discard to use up? Try my sourdough banana pancakes or my sourdough chocolate chip cookies.
Storing Leftovers
Room Temp: If the cake is frosted, cover it loosely and keep it at room temperature for up to 2 days. A cake dome or an inverted bowl works great.
Refrigerator: For longer storage, cover the cake tightly and refrigerate for up to 5 days. Let it come to room temperature before serving so the buttercream softens up.
Freezer: This cake freezes well. Wrap individual slices (or the whole cake) tightly in plastic wrap, then place in a freezer-safe container. Freeze for up to 2 months.
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Sourdough Discard Chocolate Cake
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Ingredients
- 1 cup unsweetened cocoa powder, 84 grams
- ¾ cup hot coffee, or very hot water 170 grams
- 1¾ cups granulated sugar, 350 grams
- ¾ cup vegetable oil, 160 grams
- 2 large eggs
- ¾ cup sourdough discard, 170 grams
- ½ cup milk, 113 grams
- 2 tsp vanilla extract
- 1¼ cups all-purpose flour, 150 grams
- 1½ tsp baking powder
- 1½ tsp baking soda
- 1¼ tsp salt
Chocolate Buttercream Frosting
- 1 cup unsalted butter, room temp, 226 grams
- ¾ cup unsweetened cocoa powder, 63 grams
- 3½ cups powdered sugar, sifted; 420 grams
- ¼ cup milk, plus more as needed
- 2 teaspoons vanilla extract
- ¼ teaspoon salt
Instructions
- Preheat the oven to 350°F. Line the bottom of a 13×9-inch cake pan with parchment paper. Grease and flour the sides of the pan (no need to line the sides with parchment).
- In a large mixing bowl, whisk together the hot coffee and cocoa powder until smooth. Let it sit for 2–3 minutes to bloom the cocoa. Stir in the sugar and oil until well combined.
- Whisk in the eggs, followed by the sourdough discard, milk, and vanilla extract. Mix until smooth.
- Sift the flour, baking powder, baking soda, and salt over the wet ingredients. Stir until just combined, making sure to scrape the bottom and sides of the bowl. The batter will be thin.
- Pour the batter into the prepared pan and bake for 33–38 minutes, or until a toothpick inserted in the center comes out clean.
- Let the cake cool in the pan for 5–10 minutes. Run a knife around the edges to loosen, then either leave it in the pan for serving or invert it onto a wire rack to cool completely before transferring to a serving platter.
Make the Frosting
- Beat the butter in a large bowl until pale and fluffy, 2–3 minutes.
- Add cocoa powder and mix until smooth.
- Gradually mix in the powdered sugar, starting on low and increasing speed as it incorporates.
- Add the milk, vanilla, and salt. Beat until smooth and fluffy, about 2–3 minutes.
- Adjust consistency: add more milk 1 teaspoon at a time if it’s too thick, or more powdered sugar if it’s too soft.
Frost the Cake:
- Once the cake is completely cool, spoon the frosting onto the center and spread it evenly over the top. If the cake is still in the pan, you can skip the sides. If it’s been inverted onto a platter, feel free to frost the sides as well.
Notes
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Like this recipe? Rate & comment below!Chocolate Sourdough Cake
This sourdough chocolate cake checks all the boxes: rich flavor, tender crumb, and a no-fuss method that makes the most of your discard without tasting like it.
It’s the kind of cake that earns repeat requests, and maybe a hidden slice stashed in the back of the fridge. This one’s worth every bite.
The Ingredient Shot
The Process Photos
