This sourdough chocolate cake is a rich, decadent three layer cake that’s frosted in a fudgy dark chocolate buttercream frosting. And this cake is super easy to throw together! The cake is ready to be baked in under 30 minutes or less!
Ok friend, have you ever seen the movie Matilda? You know that scene where poor Bruce Bogtrotter has to eat that entire chocolate cake? This cake is THAT cake. And if you’re like me when you saw that scene and that giant fudgy chocolate cake with that dark chocolate fudgy frosting – you wished you could have that cake in your life.
Now that cake is yours. You’re welcome. I have been on a mission lately to use up my sourdough discard and create some delicious recipes with it. I love taking a non-discard recipe and transforming it into a sourdough version. So I found this chocolate cake recipe and played around with the amount of flour, liquids, and added in my discard to create this sourdough chocolate cake version complete with my chocolate buttercream frosting.
And when I took my first bite. The heavens opened. Birds sang. And I just kept repeating the word wow over and over again.
Why You Will Love This Recipe
- No Mixer Required – This sourdough chocolate cake honestly couldn’t be easier to throw together. You can make the cake batter with just a whisk and a spatula, and a couple mixing bowls.
- This is a showstopper. Have a birthday coming up? Or want to impress your guests? This giant layer cake will definitely impress.
- Make Ahead. I love making a cake 1-2 days ahead of time and having an impressive dessert that’s ready for me the day of a special occasion.
- Cocoa Powder – You want to use unsweetened cocoa powder for this sourdough chocolate cake not dutch cocoa which will react differently with the leavening agents. Natural cocoa and dutch cocoa are different.
- Buttermilk – You want to use buttermilk not regular milk. Regular milk will not react the same. If you don’t have any, you can make a homemade buttermilk.
Use Sourdough Discard
These is of course a sourdough chocolate cake so we are using our discard from when we feed our starter. When I feed my starter fresh flour and water I remove half of the original starter and move it to a second jar. That jar is my “discard” and I keep this in my fridge for about a month.
I keep a jar of discard in the fridge and when I have enough built up I use it in a discard recipe. So this means it’s not “active” and isn’t what is responsible for making our baked goods rise, but replacing some of the flour and liquids called for in our recipe. I usually keep a jar going for a month, then start it over again.
Heather’s Baking Tip: If you find your discard has some gray liquid on top, called hooch, just simply pour this off. It’s harmless and won’t affect your discard.
If you haven’t gotten around yet to making your sourdough starter, and have no discard then let’s get going! What are you waiting for? It will take about 5 days to make your starter and have a discard worth using. But it will be worth it. Here is the full guide on How To Make Sourdough Starter From Scratch.
Once you have your starter raring to go then you will need to feed and mantain your starter.
Want to jump in to sourdough but don’t want to make your own starter? Totally fine! Just buy a sourdough starter and it will be ready to use faster.
How To Make This Sourdough Chocolate Cake
Step 1: Combine Dry Ingredients
In a large bowl you want to whisk together the flour, sugar, cocoa powder, baking powder, baking soda, and salt. Make sure it’s all evenly combined.
Heather’s Baking Tip: This makes A LOT of cake batter! Be sure to choose a large enough bowl. I used a 6-quart mixing bowl. If you do have a stand mixer bowl that might be the perfect large bowl if you don’t have any other bowls.
Step 2: Add The Wet Ingredients
To the dry ingredients, you want to stir in the wet team – eggs, buttermilk, water, vegetable oil, sourdough discard and vanilla. I switched to a spatula at this point. You just need to stir it all together until the last of the dry ingredients have been mixed in.
Baking 101: Once your dry ingredients are added to the wet ingredients you have to be careful to not overmix. Overmixing results in gluten forming and this changes the texture. Too much gluten = tough cake. So stop mixing once the flour has just mixed in.
Step 3: Baking The Cakes
This chocolate cake batter gets divided between three 9-inch round cake pans. You want to make sure to grease and flour your cake pans first before you do. I like to use a cooking spray with flour so it’s nice and quick!
Each cake pan will need about 3 cups of batter. I weighed mine out and it took about 700 g per cake pan.
You want to bake the cakes on a center rack of your oven at 350oF/170oC for about 30-35 minutes. You want to test to see if the cake is done by inserting a toothpick or wooden skewer. You should see some moist crumbs.
Heather’s Baking Tip: Another way to tell if the cake is done, is gently press the top of the cake with your finger. The cake should bounce back, not stay indented. If it stays indented, then it needs more baking time.
Now it’s time for the frosting! Did your heart just skip a beat? Mine too. I made a double batch of my chocolate buttercream frosting and use Hershey’s Special Dark cocoa powder. Here is what you need:
Making The Frosting
To make the frosting I start by mixing the butter in my bowl to cream that first. Then I add my powdered sugar about a 1 cup at a time and mix that until combined.
I then add my heavy cream, vanilla, and cocoa powder. I mix the frosting for about 7-8 minutes on medium-high speed until light and fluffy. You can always adjust the consistency add additional heavy cream if needed.
And once the cakes are cooled you can go ahead and frost this layer cake.
You can. Just divide the ingredients by 2/3 (it’s even easier if you weigh the ingredients). For the eggs, if doing by weight you can crack all 4 eggs, scramble them and then weigh out what you need. Or if by volume, just use 3 eggs.
For the frosting I used Hershey’s Special Dark dutch cocoa. But you can always use regular cocoa powder instead, it will just be lighter in color.
Yes you can. I like to make the cake layers up to 2 days ahead of time. I then wrap them in plastic wrap well and keep stored on the counter. And then I’ll frost the day before. II likeYou can also make the frosting 3 days ahead of time (store in the fridge and then rewhip again before frosting).
More Recipes To Try
Sourdough Chocolate Cake:
- 2 1/2 cups (300 g) all-purpose flour
- 3 cups (594 g) granulated sugar
- 1 1/2 cups (126 g) unsweetened cocoa powder
- 1 tablespoon baking soda
- 1 1/2 teaspoons baking powder
- 1 1/2 teaspoons salt
- 4 large eggs
- 1 1/2 cups (360 mL) buttermilk
- 1 ¼ cups (300 mL) warm water
- 1/2 cup (120 mL) vegetable oil
- 2 teaspoons vanilla extract
- 120 g (generous ½ cup) sourdough discard
Chocolate Frosting (this is a double batch!)
- 2 ½ cups (565 g, 40 Tbs.) unsalted butter softened
- 5 cups (565 g) confectioners sugar
- 1 ½ cups (126 g) Dutch cocoa powder
- 4 teaspoons vanilla extract
- 4 Tablespoons heavy cream or more as needed
- ⅛ teaspoon kosher salt
To make the cake:
- Preheat oven to 350 degrees Fahrenheit. Grease and flour three 9-inch cake rounds.
- In a large mixing bowl, whisk together flour, sugar, cocoa, baking soda, baking powder, and salt until combined.
- In the same mixing bowl, add eggs, buttermilk, water, oil, and vanilla. Stir together until smooth.
- Divide batter among the three pans (about 3 cups/700 g for each pan).
- Bake for 30-35 minutes in a 350 degree oven until a toothpick inserted into the center comes out clean.
- Cool on wire racks for 15 minutes and then turn out the cakes onto the racks and allow to cool completely.
- Frost with your favorite frosting and enjoy!
To make the frosting:
- In the bowl of your stand mixer fitted with the paddle attachment, beat the softened butter on medium speed for about 1-2 minutes, until it’s worked around the sides of the bowl. Can also be done with a hand mixer but will take longer.
- Add in the powdered sugar, with the mixer off, 1 cup at a time, and mix on low until combined.
- Add heavy cream, vanilla, and cocoa powder. Start the mixer on low, and then increase to medium to medium high speed and beat until combined for about 7-8 minutes. If frosting seems too thick you can always adjust the consistency and add 1-2 tablespoons of additional heavy cream. The frosting should be thick and will thicken even more if refrigerated. I always place back in the refrigerator to re-whip again to soften the consistency if I make the frosting ahead of time before I frost the cake.
- To assemble the cake: Place first layer onto cake platter/stand. Frost the top of the first layer. Top with second layer and repeat. Then top with third layer and frost top and sides.