This Sourdough Discard Chocolate Cake is a chocolate lover’s dream! It’s moist, rich, and easy to whip up using leftover sourdough starter. Who knew waste could taste so good?
I love making this cake because it’s a perfect way to use up starter and enjoy a sweet treat. Add some frosting, or serve it warm with ice cream for a fun dessert! 🍰
Key Ingredients & Substitutions
Sourdough Starter Discard: This is the star of the cake! It adds moisture and a slight tang. If you’re out of discard, you could use unsweetened applesauce for moisture, but it won’t have the same flavor depth.
Cocoa Powder: Unsweetened cocoa gives the cake its rich chocolate flavor. In a pinch, you can use Dutch-processed cocoa powder, but the taste will be slightly milder.
Vegetable Oil: This keeps the cake moist and tender. You can substitute with melted coconut oil or melted unsalted butter if you prefer. Just remember that butter adds extra flavor!
Buttermilk: This adds fluffiness to the cake. If you don’t have buttermilk, you can make your own by mixing milk with a bit of vinegar or lemon juice and letting it sit for 5-10 minutes.
How Do I Ensure My Cake is Extra Moist?
To get that perfect moist texture, be careful not to overmix your batter. Mix just until combined and then gently fold in the hot water or coffee. This keeps your cake light and fluffy. It’s also crucial to let the cake cool properly before frosting, as warm layers can make frosting melt off.
- Start by preheating your oven, and don’t skip greasing and flouring your pan!
- Keep an eye on the baking time; check for doneness a few minutes early. Every oven is different!
Enjoy baking and feel free to get creative with this fantastic recipe!

Sourdough Discard Chocolate Cake
Ingredients You’ll Need:
For the Cake:
- 1 cup sourdough starter discard (unfed)
- 1 cup all-purpose flour
- 1 cup granulated sugar
- 1/2 cup unsweetened cocoa powder
- 1/2 tsp baking soda
- 1/4 tsp salt
- 1/3 cup vegetable oil
- 1 large egg
- 1 tsp vanilla extract
- 1/2 cup buttermilk (or milk with 1/2 tsp vinegar/lemon juice)
- 1/2 cup hot water or brewed coffee (to enhance chocolate flavor)
For the Chocolate Frosting:
- 1/2 cup unsalted butter, softened
- 2/3 cup unsweetened cocoa powder
- 3 cups powdered sugar
- 1/3 cup milk
- 1 tsp vanilla extract
How Much Time Will You Need?
This delicious Sourdough Discard Chocolate Cake takes about 15 minutes to prep and 30-35 minutes to bake. After baking, let it cool for about 10 minutes in the pan before transferring it to a wire rack. If you’re making the chocolate frosting, allow an additional 10-15 minutes. So, overall, you’re looking at around 1 hour to 1 hour and 15 minutes total before it’s ready to serve!
Step-by-Step Instructions:
1. Preheat Oven and Prepare Pan:
First, preheat your oven to 350°F (175°C). Grease and flour an 8-inch round cake pan or simply line it with parchment paper for easy removal later.
2. Mix Dry Ingredients:
In a large bowl, sift together the flour, cocoa powder, baking soda, salt, and granulated sugar. This helps ensure no lumps and combines the dry ingredients evenly.
3. Combine Wet Ingredients:
In another bowl, whisk together the sourdough discard, vegetable oil, egg, vanilla extract, and buttermilk until the mixture is smooth and creamy. This helps incorporate air into the batter and adds richness.
4. Make the Batter:
Pour the wet mixture into the bowl with the dry ingredients. Mix them together gently until just combined. Be careful not to overmix! Next, slowly add the hot water or brewed coffee and stir gently until the batter is smooth and slightly runny.
5. Bake:
Pour the batter into the prepared cake pan. Bake in the preheated oven for 30-35 minutes, or until a toothpick inserted into the center comes out clean. Be sure to check a few minutes early, as ovens may vary.
6. Cool:
Once baked, let the cake cool in the pan for about 10 minutes. Then, carefully turn it out onto a wire rack to cool completely before frosting. This step is essential to avoid melting the frosting!
7. Prepare Frosting:
In a mixing bowl, beat the softened butter until creamy. Add the cocoa powder and mix until smooth. Gradually add the powdered sugar, alternating with milk, and beat until the frosting reaches a spreadable consistency. Stir in a teaspoon of vanilla extract at the end.
8. Frost Cake:
Once the cake is completely cool, spread the chocolate frosting evenly over the top and sides. You can go for a simple spread or create swirls and designs for a decorative touch!
9. Serve:
Slice the cake and serve as is, or enjoy it with a scoop of your favorite vanilla ice cream for an extra treat. Each bite offers a delightful chocolate flavor with a unique sourdough twist!
Enjoy this moist and rich chocolate cake made perfect with the tangy depth from the sourdough discard!
Can I Use Active Sourdough Starter Instead of Discard?
Yes, you can use active sourdough starter, but it’s best to reduce the amount of liquid in the recipe slightly since active starter may contain more moisture than discard. You can decrease the buttermilk by a couple of tablespoons to maintain the right batter consistency.
How Should I Store Leftovers?
Store any leftover cake in an airtight container at room temperature for up to 3 days. For longer storage, you can refrigerate it for up to a week or freeze slices wrapped in plastic wrap and foil for up to 3 months. Just make sure to thaw in the fridge before enjoying!
Can I Make This Cake Vegan?
Yes! To make this cake vegan, substitute the egg with a flax egg (1 tablespoon ground flaxseed mixed with 2.5 tablespoons water), use a plant-based milk in place of buttermilk, and opt for coconut oil or another plant-based oil in place of vegetable oil. The cake will still be moist and delicious!
What Can I Use If I Don’t Have Cocoa Powder?
If you’re out of cocoa powder, you can use a carob powder as a substitute, though it will give a different flavor. For a more unique approach, you might try adding melted dark chocolate instead, keeping in mind to adjust the fat content accordingly.
