Overnight Sourdough Chocolate Cake
This chocolate sourdough cake is soft and tender with deep chocolate flavour, filled and topped with creamy chocolate frosting. It is the perfect way to use your sourdough discard starter and makes the best chocolate cake. I like to make the batter the day before and ferment it in the fridge overnight, though you can bake it all in one day too.
About this recipe
This sourdough discard chocolate cake is 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 starter discard recipes include puff pastry and overnight sourdough pancakes. This sourdough cake recipe doesn’t rely on the yeast in the starter the way that sourdough bread does. It uses the acid produced by the Lactobacillus bacteria in the starter. 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.
Ingredients
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. I prefer the taste of natural cocoa powder though.
- 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
I like to make the batter the night before and leave it to ferment in the fridge overnight. This helps break down the starches in the flour and helps with digestion. I have done a side-by-side test of baking the batter all in day one versus an overnight ferment and found no real difference in the height of the cakes when baked or the flavour, so it’s an optional step.
Method
- 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.
- Cover the bowl tightly and ferment overnight, or go right to baking.
- Divide the batter evenly over two 8-inch cake pans and bake.
- Mix the frosting by beating butter until creamy, then powdered sugar, cocoa powder, milk, vanilla, and salt til creamy.
- Spread 1/3 of the buttercream on one cake round so it reaches the edges. Add the second cake round on top. Spread with the remaining buttercream.
FAQs about sourdough chocolate cake
Variations
- Sourdough chocolate orange cake: Add the zest of an orange into the batter, and replace half of the milk with fresh orange juice.
- 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.
Related recipes
Keen to make some other delicious recipes? Try this sourdough red velvet cake or other sourdough recipes that are not bread, like sourdough croissants or homemade sourdough waffles.
Sourdough Chocolate Cake
Ingredients
Cake batter
- 220 g all-purpose flour
- 70 g cocoa powder unsweetened. I prefer natural cocoa powder
- 3/4 tsp salt
- 1 tsp baking powder
- 1 tsp baking soda
- 2 large eggs
- 1 tsp vanilla extract
- 180 g vegetable oil
- 100 g sourdough discard starter
- 130 g granulated sugar
- 130 g soft brown sugar
- 240 g milk
- 120 g coffee hot and strong
Chocolate Buttercream
- 226 g butter softened to room temperature
- 300-375 g powdered sugar
- 30 g cocoa powder
- 1/2 teaspoon vanilla paste
- 2-3 Tbsp milk or cream at room temperature
- 1/4 tsp salt
Instructions
- 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.
- Fermenting overnight (optional) – Cover the bowl tightly and refrigerate for up to 12 hours.
- Heat the oven to 180°C (350°F). Grease and line two 8-inch round cake pans.
- Pour into the prepared cake pans and bake for 25-30 minutes until a skewer inserted into the cakes comes out clean.
Chocolate Buttercream
- 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.
- Spread 1/3 of the buttercream on one cake round so it reaches the edges. Add the second cake round on top. Spread with the remaining buttercream.
Have you tried baking the chocolate cake in a Bundt pan? I thought that might be nice too. I’m going to try it. Thanks for the recipe.
Hey Kathy, I haven’t tried that yet but if you do I’d love to know how it goes!
Dio i need to feed the discard sourdough starter and let it be active before use? For use:
Nope it’s unfed starter 🙂
Question before I begin. Can I possibly use white chocolate chips for the Ganache & color it with food coloring for a blue finish? 😄
Hey yes you can use white chocolate for the ganache, yum! Though for the colouring part I’m not sure at what stage is best to add the colour but I’m sure there is plenty of information out there for that 🙂
Hi!
I’m interested in making the cake and it looks delicious. However, it looks like there is a chocolate ganache over the buttercream yet it is s not listed in your ingredients or description anywhere. Can you help? Is there a ganache poured over or a separate chocolate frosting on top of the butter cream?
Heya, it’s a seperate ganache that’s poured over the buttercream at the end. It’s 3/4 cup cream heated until steaming, then it’s taken off the heat and 1 cup of chocolate chips are added and left to melt for 5 minutes before being stirred in to create a glossy chocolate mixture. Leave it to cool for a little while to slightly thicken, the pour it over the cake 🙂
Hi! I’m just starting with sourdough, and am using your starter recipe. When you say 100% hydration in this cake recipe what do you mean exactly? Just that amount of starter from your starter recipe or do I do something different?
I just mean the starter itself was fed equal parts water and flour in weight 😊. So if you’re using my starter recipe, then yeah it’s just that.
Can you use a bundt cake pan?
We made this tonight and my kids would not wait for it to cool and be iced. Everyone loved it! We’ll see how they like it tomorrow with ganache on it. Thank you! Love finding recipes to keep the sourdough starter in use.
So glad you loved it! 😄
Hi, I’m just up to Day in making my first starter. Can you use the discard from Day 3 for this recipe? 😊
Hey, I think you could though it won’t as acidic as more mature sourdough starter so the cake may not be as light. I think it will still work though.
Umm, yeah….I’m gonna need to get that buttercream recipe as well…..
I have added it in! 😀
Any chance you can give the weights in grams too? Or an idea of what one cup of flour weighs to you?
Hey, I have added all my weights in grams too. Such a good point, as I forget how much it can change depending on country/cups size/ measuring style! Thanks 🙂