Gluten Free Sourdough Chocolate Cake with Discard

This gluten free sourdough chocolate cake is a rich, moist, and flavorful twist on a classic gluten free chocolate cake. The batter includes gluten free sourdough starter, which adds subtle tang, extra moisture, and a deeper chocolate flavor. If you have been looking for an easy sourdough discard dessert, this one-bowl chocolate cake is a wonderful place to start. It comes together with simple ingredients, requires very little prep time, and bakes into a soft, tender cake. Finished with a dark chocolate sour cream frosting, it is the kind of everyday gluten free cake that feels special without being complicated.

Recipe Ingredient Notes

Gluten Free Flour: This gluten free sourdough chocolate cake has been tested successfully with a homemade gluten free flour blend, Bob’s Red Mill 1-to-1, and King Arthur Measure for Measure. Each blend produced a light, tender crumb. Other gluten free flour blends may work, but they have not been tested for this specific recipe.

Gluten Free Sourdough Discard: Sourdough discard is the portion of gluten free sourdough starter removed during feeding. For this chocolate sourdough discard cake, use unfed gluten free sourdough starter. It adds moisture, a gentle tang, and a more developed flavor to the cake batter.

Cocoa Powder: Dutch-processed cocoa powder is recommended because it gives this cake a deep, rich chocolate flavor. A dark cocoa powder also works well for quick bakes like this one-bowl gluten free chocolate cake.

Neutral Oil: Oil helps create a soft and airy cake texture. Since oil stays liquid at room temperature, it coats the flour more evenly and supports a finer crumb. Vegetable oil or grapeseed oil both work well. Coconut oil is not recommended for this recipe.

Hot Coffee: Hot coffee strengthens the chocolate flavor and balances the sweetness in the cake. It does not make the cake taste strongly like coffee; instead, it makes the chocolate taste richer. If you prefer a coffee-free dessert, use hot water instead.

Sour Cream Frosting: The dark chocolate sour cream frosting adds a smooth, rich finish with a slight tang from the sour cream. Regular unsalted butter is used, but the frosting can also be made with dairy free butter and dairy free sour cream if needed.

What is Sourdough Discard?

Sourdough discard is the part of a sourdough starter that is removed before fresh flour and water are added. A sourdough starter is a mixture of flour and water that captures wild yeast and bacteria from the environment. Over time, the mixture ferments and becomes active enough to use in baking.

Although it is called “discard,” it does not have to be thrown away. In recipes like this gluten free sourdough discard chocolate cake, it can be used to add flavor, moisture, and texture. Using discard in baked goods is also a practical way to reduce waste while enjoying the flavor benefits of sourdough fermentation.

Why add Sourdough Discard to Chocolate Cake

Adding sourdough discard to a gluten free chocolate cake improves the flavor and texture in several ways.

Flavor enhancement: The fermentation in sourdough discard brings a mild tang that pairs beautifully with chocolate. It makes the cake taste more complex without overpowering the sweetness.

Moisture: Sourdough discard contains water, which helps keep the cake tender and moist. This is especially helpful in gluten free baking, where cakes can dry out more quickly.

Texture: While discard is not as strong as an active starter, it may still contain wild yeast and lactic acid bacteria. These can contribute to a slightly lighter texture, giving the cake a softer crumb.

How to make a Sourdough Chocolate Cake

A 9-inch springform pan works well for this gluten free one-bowl chocolate cake. You can also use an 8×8-inch or 9×9-inch square pan. A 9×13-inch pan is not recommended unless you double the recipe, as the cake will be very thin.

Step 1: Preheat the oven to 350°F. Lightly grease the springform pan with nonstick cooking spray and line the bottom with parchment paper. Set it aside.

Step 2: In a bowl, combine the gluten free flour, cocoa powder, baking powder, baking soda, and kosher salt. Sift or whisk the dry ingredients well, especially if the cocoa powder is lumpy.

Step 3: In a large mixing bowl, combine the granulated sugar, oil, and room-temperature eggs. Whisk until smooth and fully combined.

Step 4: Add the unfed sourdough discard and vanilla extract. Whisk until the mixture is smooth. The consistency of sourdough discard can vary depending on the gluten free flours used in the starter.

Step 5: Add the dry ingredients to the wet ingredients. Mix with a whisk or spatula until the batter is smooth and no dry streaks remain.

Step 6: Slowly pour in the hot coffee or hot water while stirring continuously. The batter will become thin, which is normal.

Step 7: Pour the gluten free sourdough chocolate cake batter into the prepared pan. Smooth the top with a small offset spatula or the back of a spoon.

Step 8: Bake at 350°F for 35 to 40 minutes, or until a toothpick inserted into the center comes out clean. The top should spring back gently when touched. Avoid overbaking, as this can make the cake dry. Baking time may vary depending on your oven and pan.

Step 9: Remove the cake from the oven and let it cool on a wire rack for 10 to 15 minutes before removing it from the pan. If the cake sticks, carefully run a butter knife around the edge. Cool completely before frosting.

Dark Chocolate Sour Cream Frosting

This gluten free sourdough chocolate cake is finished with a dark chocolate sour cream frosting. The frosting is rich, smooth, and slightly tangy, which balances the sweetness of the cake. If you prefer a different flavor, salted caramel buttercream, peanut butter frosting, or cream cheese frosting would also pair well with this chocolate cake.

The frosting can be made in a stand mixer fitted with the paddle attachment or in a large bowl with an electric hand mixer.

To make the frosting, bring a medium saucepan filled with 1 inch of water to a simmer. Place the bittersweet chocolate in a heatproof bowl and set the bowl over the simmering water, making sure the bowl does not touch the water. Melt the chocolate, then let it cool slightly.

In a large bowl, beat the room-temperature butter and kosher salt on medium speed until smooth and creamy, about 5 to 7 minutes. Beat in the vanilla extract and melted chocolate until fully incorporated. Add the powdered sugar in three additions, scraping down the bowl between each addition. Fold in the sour cream with a rubber spatula until no white streaks remain.

Once the cake is completely cool, transfer it to a serving platter and spread a generous layer of frosting over the top. Garnish with gluten free sprinkles, chocolate shavings, mini chocolate chips, toasted nuts, or any topping you like.

Let the frosted cake chill in the refrigerator for about 10 minutes before slicing. For clean slices, use a sharp knife warmed in hot water and dried thoroughly. Wipe the knife clean between cuts to keep the frosting neat.

Storage & Freezing

Store this gluten free one-bowl chocolate cake in an airtight container at room temperature for up to 3 days, or in the refrigerator for up to 5 days. The cake tastes even better on the second day once the flavors have had time to develop. If refrigerated, let the cake sit at room temperature for 15 to 20 minutes before serving.

To freeze the unfrosted gluten free chocolate cake, allow it to cool completely first. Wrap the cake tightly in plastic wrap, covering the entire surface to prevent freezer burn. For extra protection, place the wrapped cake in an airtight container. Freeze for up to 2 months. Thaw in the refrigerator, then frost before serving.

Individual leftover slices can also be frozen in an airtight container for up to 1 month. Thaw slices at room temperature before eating.

FAQ – Sourdough Chocolate Cake

Note about Salt in my Recipes

I use Diamond Crystal kosher salt in my recipes unless noted otherwise. If you use another brand or type of salt, adjust as needed because saltiness can vary. Morton’s kosher salt has smaller, denser granules and tastes saltier by volume.

Baking in grams

These recipes are shared in grams because baking by weight is the most accurate method. This is especially important in gluten free baking, since gluten free flours can vary greatly in weight and texture. Measuring cups can lead to inconsistent results, while a digital scale helps keep the recipe precise and repeatable. Small amounts, such as leavening agents and spices, may still be listed in measuring spoons.

Note about Ovens and Oven Temperatures

All recipes are tested in a conventional oven. Baked goods are placed on the middle rack so the heat circulates evenly and the bottom does not burn. If you bake with convection or a fan-forced setting, adjust the temperature and baking time as needed. Convection heat can dry baked goods quickly while the center may still be underbaked.

Substitutions and Modifications

Any ingredient substitutions or dietary modifications may change the appearance, texture, and flavor of this gluten free sourdough chocolate cake. The recipe has been tested as written, and results may vary when ingredients are changed.