Sourdough Chocolate Cake- Easy Sheet Pan Recipe

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This sourdough chocolate cake is baked in a sheet pan for an easy, crowd-pleasing dessert. Rich, moist, and simple to make, it’s the perfect recipe for birthdays, potlucks, or weeknight treats.

As a homemaker and homeschool mom of five, I’ve learned that the great thing about baking isn’t just the delicious end result—it’s the memories made around the table. Plus I’ve learned how important it is to keep recipes simple, approachable, and nourishing.

Between school lessons, errands, and the whirlwind of a busy household, I’m always on the hunt for delicious recipes that feel doable. This sourdough chocolate cake recipe is one of my favorites: a no-fuss sheet pan bake that turns basic pantry staples and a little sourdough starter discard into a rich chocolate cake everyone will rave about.

Recently, during a cozy family movie night while we watched Matilda, I whipped up this sourdough discard chocolate cake as a sweet surprise. It was such a great way to make a simple night at home feel like a special occasion. The rich flavor and tender moist cake texture make it the best chocolate cake for birthdays, potlucks, or even a next day treat tucked into lunchboxes.

Why Make Chocolate Cake with Sourdough?

Using discard sourdough starter in a chocolate cake might sound unusual, but it’s a perfect recipe for reducing food waste and making the most of your own starter. The natural acidity in active sourdough starter or sourdough discard helps tenderize the crumb, creating an incredibly moist cake. It also adds a subtle tang that balances the rich chocolate flavor without overpowering the sweetness. I love this about sourdough!

Another great thing about sourdough in desserts is flexibility—you can use fed starter (an active starter) or discard straight from the fridge. No need for extra steps: just add it to your wet ingredients and watch the cake rise beautifully in the preheated oven.

For sourdough lovers who already bake sourdough bread, this cake is a fun addition to your sourdough discard recipes. And if you’re new to sourdough, this is a gentle introduction—you don’t need to knead or shape anything, just stir and bake.

What You’ll Love About This Recipe

Easy sheet pan format – Forget multiple cake layers and fussy decorating. Bake once in a greased cake pan, frost, and serve.
Flexible ingredients – Use vegetable oil or coconut oil, and either fed starter or discard.
Chocolate lovers approved – The chocolate buttercream frosting amplifies the rich chocolate flavor, making it a best cake contender.
No special equipment required – While a stand mixer with a paddle attachment is handy, you can also use a hand mixer or even a whisk and large mixing bowl.

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Key Ingredients

Here’s what makes this cake special:

Sourdough discard – Adds tang, moisture, and reduces waste.
Quality cocoa powder – Dutch cocoa or dutch process cocoa deepens the rich chocolate flavor.
Vegetable oil or coconut oil – Keeps the cake tender and moist.
Vanilla extract – Enhances chocolate’s natural sweetness.
Powdered sugar – For a creamy chocolate buttercream frosting.

You’ll find the complete ingredient amounts in the recipe card at the bottom of this post.

How to Make Sourdough Chocolate Cake with Discard

Here are the steps for this chocolate sourdough cake:

Mix and Rest the Starter Mixture—In a large bowl, whisk together sourdough discard, whole milk, and all-purpose flour. Cover the bowl with plastic wrap or a clean towel. Let it rest at room temperature for 2–3 hours. This resting time allows the flour to hydrate and gives the starter time to work, improving the cake’s texture.

Prepare Your Pan and Oven—Preheat your oven to 350°F. Grease a 9×13-inch pan (a sheet pan style works perfectly) or line it with parchment paper to create a sling for easy removal. Either a greased cake pan or parchment sling will help prevent sticking.

Combine the Wet Ingredients—In the bowl of a stand mixer fitted with the paddle attachment, beat together: sugar, vegetable oil or coconut oil, vanilla extract, salt, baking soda, and cocoa powder (Dutch cocoa or standard unsweetened). Mix on low speed at first to avoid a cocoa cloud, then increase slightly. Scrape down the sides of the bowl a couple times to ensure everything is combined.

Add the Eggs—eggs, one at a time, mixing just until incorporated. Avoid high speed mixing here—you don’t want to overbeat.

Combine Mixtures—Pour the sourdough mixture into the chocolate mixture. Beat on low speed until a thick cake batter forms. At first, it may seem gloppy or separated—keep mixing. The batter will smooth out and become glossy and uniform.

Bake—Pour batter into the prepared pan. Bake for 30–40 minutes, or until the center of the cake springs back when lightly pressed. A cake tester or toothpick should come out with only moist crumbs—not wet batter.

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Cool the cake on a cooling rack while you prepare the frosting. Letting it cool completely ensures the top of the cake won’t tear or melt the frosting.

Make the Chocolate Buttercream Frosting—In the bowl of a stand mixer with the paddle attachment, cream together the butter and cocoa powder. Next add in 3 cups of powdered sugar and combine. Add vanilla and heavy cream and mix until smooth and spreadable.

Frosting & Topping Ideas

Classic chocolate frosting spread thickly across the top of the cake.
Sprinkle mini chocolate chips or shaved chocolate for texture.
Add colorful sprinkles for birthdays or a second layer of decoration.
Drizzle with ganache made in a small saucepan with heavy cream and chocolate.

Baking Tips & Storage

Use room temperature ingredients for the eggs and dairy—this helps the cake rise evenly.
Always use a kitchen scale for accuracy if possible. Weighing your dry ingredients ensures consistent results.
A bundt pan or bundt cake shape works if you want a fancier look—just adjust the bake time slightly.
To store, cover the cake tightly with plastic wrap or transfer slices to an airtight container. It will stay fresh on the serving plate at room temperature for up to three days.
For longer storage, freeze slices individually wrapped. Thaw in the fridge overnight and frost the next day if freezing the whole cake unfrosted.

Recipe FAQs

Can I use active starter instead of discard?

Yes! Active sourdough starter works perfectly. The flavor will be slightly less tangy, but the moist crumbs and rich flavor remain the same.

What if I don’t have a stand mixer?

No worries—a hand mixer or even a sturdy whisk with a whisk attachment works. Just take your time mixing the wet ingredients and dry ingredients.

Can I make a layer cake instead?

Absolutely. Divide the cake batter between two 8-inch pans or inch pans, bake, and stack for a layer cake. Frost the second layer generously for a bakery-style presentation.

What substitutions can I make?

If you’re out of vegetable oil, try olive oil for a unique depth of flavor.

Does this work as cupcakes or in other pans?

Yes—cupcakes, bundt cake, or even a thinner sheet pan version all work. Adjust bake times and check with a cake tester.

More Sourdough Dessert Recipes

If you’re hooked on sourdough discard recipes, here are more to try next time:

Why This Sourdough Chocolate Cake Belongs in Your Rotation

This chocolate sourdough cake checks all the boxes:

It’s budget-friendly and reduces food waste.
It’s approachable, even for beginner bakers.
It delivers bakery-quality results—the best cake you’ll make on a weeknight.

The rich chocolate cake pairs perfectly with a tall glass of milk or a cup of coffee. And the chocolate buttercream frosting? It’s so luscious you’ll be tempted to eat it straight from the bowl (I may have done this a couple times!).

Plus, the sheet pan format is forgiving—no fancy decorating required. Slice squares right in the pan, cover with plastic wrap, and bring it to the next potluck. It’s also a perfect recipe for kids to help with: let them pour batter, stir the dry ingredients, or decorate the top of the cake with sprinkles.

Closing Thoughts

This sourdough discard chocolate cake proves that even a busy weeknight can hold a little magic. Baking doesn’t need to be complicated or time-consuming to be extraordinary. With a large bowl, a stand mixer, and a bit of sourdough starter discard, you can create the best chocolate cake your family has ever tasted—one that brings people together and makes memories sweeter.

Whether you’re sharing it at a birthday, packing it for a picnic, or savoring a slice after dinner, this chocolate sourdough cake is a reminder that small, simple efforts can create big joy. So the next time you feed your starter, set aside a cup of discard—you’ll thank yourself when you pull this rich chocolate cake from the oven, the center of the cake puffed perfectly and the aroma filling your kitchen…and your family enjoying every bite.

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If you make this recipe, please leave a rating on the recipe card below! I’d also love for you to tag me @autumn.chasingoursimple on Instagram so I can see what you’ve been baking!