This chocolate sourdough cake is filled with creamy chocolate frosting and topped with a rich chocolate ganache. It is the perfect way to use your sourdough discard starter and makes the best chocolate cake.
Sourdough starter discard
This sourdough discard chocolate cake is the perfect recipe for using your excess sourdough starter! It’s a rich chocolate layer cake and makes a wonderful birthday cake or cake for any occasion.
The great thing about sourdough discard recipes is that you can save up all the starter discard in a jar in the fridge and use it when you want. Other sourdough starters discard recipes include puff pastry and overnight sourdough pancakes.
This starter hasn’t been fed in a while or passed its peak and is now very acidic. That’s not good for sourdough bread, but it’s great for this sourdough chocolate cake (or red velvet cake!) Don’t have a starter yet? Learn to make your own starter with this sourdough starter recipe.
The actual amounts of the ingredients for this tender chocolate cake recipe are written in the recipe card at the bottom of this post. Here is a rundown of what you need.
- Sugar – There’s a mixture of granulated and brown sugar for sweetness and moisture.
- Large eggs – Eggs act as a binding agent, providing structure and stability. They also add moisture and fat.
- Vanilla paste or good-quality vanilla extract – Vanilla adds depth of flavor, enhancing the chocolate.
- Discard sourdough starter – The sourdough discard contributes a unique, slightly tangy flavor, balancing the sweetness of the cake. The acid in the starter creates a tender cake.
- Vegetable oil. Oil creates a really moist cake. You could use light olive oil, liquid coconut oil, or neutral-tasting vegetable oil.
- Salt – Enhances all the flavors.
- All-purpose flour – The base of the cake.
- Whole milk – Loosens the batter.
- Cocoa powder (this can be natural cocoa powder or dutch processed cocoa powder)
- Baking powder and baking soda – The leavening agents in the cake.
- Hot coffee. I use instant espresso powder dissolved in boiling water. If you’re not a fan of coffee, don’t worry, you won’t taste it. The coffee helps to strengthen the chocolate flavor. If you want to leave it out, it can be substituted for hot water.
Fermented chocolate cake
Make the batter the night before and leave it to ferment in the fridge. This helps break down the starches in the flour and helps with digestion. Cover the bowl of cake batter tightly. This is an optional step.
This sourdough chocolate cake is best baked in two 8-inch round cake pans. It can, however be baked in one larger pan and sliced in half, but it will bake more evenly when baked in two.
Grease and line the cake pans with parchment paper.
In a large mixing bowl, whisk together the flour, cocoa, salt, baking powder, and baking soda and set it aside.
In a separate bowl, whisk together the sourdough starter, eggs, vanilla, oil, milk, and sugars.
Pour the wet ingredients into the flour mixture and fold gently for a minute before pouring over the hot coffee.
Mix the wet and dry ingredients briskly together but don’t over mix the batter.
Pour the chocolate cake batter into the greased cake pans and bake until a skewer inserted into the center of the cakes comes out clean and the top of the cakes springs back when touched.
Let the cakes cool in the pan for 5 minutes before removing and placing them on a wire cooling rack to cool completely before frosting.
In a bowl of a stand mixer fitted with a paddle attachment, beat the room-temperature butter until light and creamy.
Add the powdered sugar, cocoa powder, milk, vanilla, and salt to the butter.
Whisk on low speed to incorporate them, scraping the sides of the bowl as needed. Once incorporated, switch to medium-high speed and beat the mixture for another 1-2 minutes until it’s light and fluffy.
Switch to a rubber spatula and stir the buttercream in a spreading motion to smooth out some bubbles.
Spread ¼ of the buttercream on one cake round so it reaches the edges. Add the second cake round on top. Top this round with another ¼ buttercream and spread it out with an offset spatula.
Use the remaining buttercream to cover the edges of the cake, and use a dough scraper to smooth it out.
The ganache topping is optional but adds a real decadent touch to the chocolate cake and it’s perfect for chocolate lovers.
Heat the cream in a small saucepan until just simmering. Take it off the heat and add in chopped chocolate. Let them melt, then stir them together until glossy.
Leave the ganache to cool and thicken before pouring it on the cake so it can spread in a thick layer.
Sourdough starter adds a subtle tanginess to the cake, making the chocolate flavor more complex. Plus, it helps to leaven the cake, making it light and tender.
Yes, unfed sourdough discard works perfectly for this recipe. It’s a great way to use up, discard and minimize waste.
Store at room temperature in an airtight container for 3-4 days or, in the fridge for about a week. It can also be frozen for up to 3 months. Just make sure to wrap it well to prevent it from drying out.
- Sourdough Chocolate Orange Cake: Add the zest of an orange into the batter, and replace half of the milk with fresh orange juice. The citrus flavor pairs wonderfully with chocolate.
- Sourdough Mocha Cake: Go heavier on the coffee to add mocha flavor. Add a tablespoon of instant coffee powder to the batter to give your cake a rich mocha flavor.
- Chocolate raspberry cake: On the first layer of cake, spread out some of the frosting, then pipe a wide ring of frosting around the edge. Spoon in a layer of raspberry compote. Add the second layer of cake, and continue frosting with chocolate buttercream.
- Sourdough Mint Chocolate Cake: Add 1/4 teaspoon peppermint extract to your cake batter and 1 teaspoon peppermint extract to the chocolate buttercream frosting.
- 220g (1 3/4 cups*) all-purpose flour
- 70g (3/4 cup) cocoa powder
- 1/2 tsp salt
- 1 tsp baking powder
- 1 tsp baking soda
- 2 large eggs
- 1 tsp vanilla extract
- 180g (3/4 cup) vegetable oil
- 100g (1/2 cup) sourdough discard starter
- 130g (2/3 cup) granulated sugar
- 130g (2/3 cup) soft brown sugar
- 240g (1 cup) milk
- 120g (1/2 cup) hot strong coffee
- 226g (1 cup) butter, softened to room temperature
- 300-375g (2 1/2-3 cups) powdered sugar
- 30g (1/3 cup) cocoa powder
- 1/2 teaspoon vanilla extract or paste
- 2-3 Tbsp milk or cream at room temperature
- 1/4 tsp salt
- 125g (1/2 cup) pouring cream
- 150g (5oz) semi-sweet chocolate, chopped
- Preheat the oven to 180°C (350°F), grease, and line two 8-inch round cake pans.
- Mix the flour, cocoa powder, salt, baking powder, and baking soda in a large bowl. Set it aside.
- Whisk together the sourdough starter, eggs, vanilla, oil, milk, and sugars in a separate bowl.
- Pour the wet mixture into the flour mixture and fold gently for a minute before pouring over the hot coffee.
- Mix briskly together but don't over-mix.
- Pour into the prepared cake pans and bake for 25-30 minutes until a skewer inserted into the cakes comes out clean.
- In a stand mixer bowl fitted with a paddle attachment, beat the room-temperature butter until light and creamy.
- Add the powdered sugar, cocoa powder, milk, vanilla, and salt to the butter.
- Whisk on low speed to incorporate them, scraping the sides of the bowl as needed. Once incorporated, switch to medium-high speed and beat the mixture for another 1-2 minutes until it's light and fluffy.
- In a small saucepan, heat the cream until just simmering. Take it off the heat and add the chopped chocolate.
- Leave it to sit for 5 minutes, then stir until it is glossy and all the chocolate has melted. Let it cool down until it thickens before pouring on the cake.
* The cup sizes given are US-sized cups. Note that these are smaller than metric. For best results, use a kitchen scale and grams.
The calorie count for this recipe is for one serving of sourdough chocolate cake. It does not include the frosting or ganache topping.
The batter can be made the night before and left to ferment in the fridge. This helps with breaking down the starches in the flour.
As an Amazon Associate, a Mighty Ape affiliate and member of other affiliate programs, I earn from qualifying purchases.
Nutrition Information:Yield: 12 Serving Size: 1 slice
Amount Per Serving: Calories: 300Total Fat: 16gSaturated Fat: 12gUnsaturated Fat: 0gCholesterol: 29mgSodium: 301mgCarbohydrates: 39gFiber: 2gSugar: 24gProtein: 4g