If you have sourdough starter or discard sitting in the refrigerator, this Sourdough Cloud Cake is a lovely way to turn it into something light, soft, and slightly tangy. The cake has a delicate texture and a gentle sourdough flavor that pairs beautifully with vanilla and a light dusting of powdered sugar.
Unlike a traditional dense cake, a cloud cake is all about keeping the batter light and airy. The eggs do much of the work, creating a soft structure that gives the finished cake its characteristic fluffy texture.
This recipe is simple enough for a weekend bake but special enough to serve with afternoon tea or coffee. It is also a useful recipe when you have extra sourdough discard that you don’t want to waste.
Why You’ll Love This Sourdough Cloud Cake
There are several reasons this cake is worth trying.
First, it gives leftover sourdough starter a purpose. Instead of throwing away discard, you can use it to add flavor and moisture to a homemade cake.
Second, the texture is especially light. Whipped egg whites create tiny air bubbles throughout the batter, helping the cake rise into a soft and delicate crumb.
The flavor is subtle rather than strongly sour. Vanilla balances the fermented flavor, while a small amount of lemon zest can add a fresh note if desired.
The cake is also versatile. You can serve it plain, dust it with powdered sugar, or add fresh berries and a little whipped cream.
Ingredients
Makes one 8-inch cake.
For the Cake
- 1 cup sourdough starter or sourdough discard
- 4 large eggs, separated
- ¾ cup all-purpose flour
- ½ cup granulated sugar
- ¼ cup neutral oil or melted butter
- 1 teaspoon vanilla extract
- 1 teaspoon baking powder
- ¼ teaspoon fine salt
- 2 tablespoons milk
- 1 teaspoon lemon zest, optional
For Finishing
- Powdered sugar, optional
- Fresh berries, optional
- Whipped cream, optional
For the best texture, use sourdough starter that is at room temperature. If your starter has been refrigerated, allow it to warm slightly before mixing.
Step 1: Prepare the Oven and Pan
Preheat your oven to 350°F (175°C).
Lightly grease an 8-inch round cake pan.
Line the bottom with parchment paper.
You can lightly grease the sides as well, but avoid using an excessive amount of oil because a very slippery pan can make it harder for the cake to climb as it rises.
Set the prepared pan aside.
Step 2: Separate the Eggs
Separate the four eggs carefully.
Place the egg whites in a completely clean, dry mixing bowl.
Put the yolks in a separate bowl.
Make sure no egg yolk gets into the whites. Even a small amount of fat from the yolk can make it difficult to whip the whites properly.
This step is important because the whipped egg whites are responsible for much of the cake’s airy texture.
Step 3: Prepare the Sourdough Batter
Add the sourdough starter to the bowl containing the egg yolks.
Add the oil or melted butter, milk, and vanilla extract.
Whisk until smooth.
Add the flour, baking powder, salt, and lemon zest if using.
Mix gently until the ingredients are combined.
Don’t overmix the batter at this stage.
The mixture may look somewhat thick. That is completely normal because the whipped egg whites will be folded in later.
Step 4: Whip the Egg Whites
Using a hand mixer or stand mixer, begin beating the egg whites on medium speed.
Once they become foamy, gradually add the sugar.
Continue beating until the egg whites form glossy medium-to-stiff peaks.
When you lift the beaters, the peaks should hold their shape.
Avoid beating the whites until they become dry or grainy.
Smooth, glossy egg whites are much easier to fold into the batter without losing too much air.
Step 5: Lighten the Batter
Add about one-third of the whipped egg whites to the sourdough batter.
Gently fold them in with a spatula.
You can mix this first portion slightly more thoroughly because its purpose is to loosen the thick batter.
Once the mixture is lighter, add another third of the egg whites.
Fold gently.
Finally, add the remaining egg whites.
Use slow, sweeping movements with the spatula, moving from the bottom of the bowl toward the top.
Stop folding as soon as the batter is mostly uniform.
A few tiny streaks are better than overmixing.
Step 6: Transfer to the Pan
Pour the batter into the prepared cake pan.
Gently smooth the top with a spatula.
Do not bang or aggressively tap the pan on the counter because that can knock out some of the air you carefully created in the egg whites.
Place the pan in the center of the preheated oven.
Step 7: Bake
Bake for approximately 30–38 minutes.
The exact baking time will depend on your oven and the depth of your cake pan.
The top should become lightly golden and spring back gently when touched.
Insert a toothpick into the center.
It should come out clean or with a few moist crumbs attached.
If the top is browning too quickly while the center still needs time, loosely cover the cake with foil during the final part of baking.
Step 8: Cool the Cake
Remove the cake from the oven and place the pan on a cooling rack.
Allow it to cool for about 10–15 minutes.
Run a thin knife gently around the edges if needed.
Carefully remove the cake from the pan and allow it to cool completely before slicing.
The crumb will continue to set as the cake cools.
Trying to slice it while it is extremely hot can make the delicate structure compress.
Step 9: Add the Finishing Touch
Once completely cool, dust the top lightly with powdered sugar.
You can serve the cake exactly as it is or add fresh berries.
For a more dessert-like presentation, add a small spoonful of whipped cream alongside each slice.
The cake is also delicious with strawberries, raspberries, blueberries, or sliced peaches.
Tips for a Fluffy Cloud Cake
Use room-temperature ingredients. Eggs and sourdough starter at room temperature generally combine more easily.
Keep the egg whites clean. Any grease or egg yolk can interfere with whipping.
Don’t overmix. Once the flour is added, mix only until combined.
Fold gently. The whipped egg whites contain the air that creates the cloud-like texture.
Don’t open the oven too early. A sudden temperature change can affect the rise.
Allow the cake to cool. The structure becomes more stable as it cools.
Sourdough Starter or Discard?
Both active starter and sourdough discard can work in this recipe.
Active starter may provide a slightly milder fermented flavor, while discard that has been sitting in the refrigerator for several days can have a more noticeable tang.
If your discard has developed a dark liquid layer called hooch, simply stir it back in or pour it off depending on your usual sourdough routine.
Always use starter that looks and smells normal for your sourdough culture. If it shows signs of mold or unusual spoilage, discard it.
How to Make the Flavor More Interesting
For a simple vanilla cloud cake, keep the recipe exactly as written.
For a citrus version, add extra lemon zest or a small amount of orange zest.
For a chocolate variation, replace a small portion of the flour with unsweetened cocoa powder.
You can also add a little cinnamon for a warm flavor that works especially well during cooler months.
Fresh berries on top can add color and a pleasant contrast to the soft cake.
Storage
Store the cooled cake in an airtight container at room temperature for up to about 2 days.
For longer storage, refrigerate it in a well-covered container.
Because refrigeration can make cakes firmer, allow refrigerated slices to sit at room temperature for several minutes before serving.
If you add whipped cream or fresh fruit, keep the cake refrigerated.
Freezing Instructions
This cake can also be frozen.
Allow it to cool completely, then wrap individual slices tightly in plastic wrap or place them in freezer-safe containers.
Freeze for up to about 2 months.
Thaw the slices in the refrigerator or at room temperature.
For the best texture, add powdered sugar, whipped cream, or fresh berries after thawing.
Serving Ideas
Serve a slice with:
- Fresh strawberries
- Blueberries or raspberries
- Whipped cream
- Greek yogurt
- Powdered sugar
- A little nut butter
- Coffee or tea
The cake is light enough for breakfast or an afternoon snack but can also work as a simple dessert.
Final Thoughts
Sourdough Cloud Cake is a delicious way to use extra starter while creating something completely different from bread.
The secret to its light texture is simple: whip the egg whites well, then fold them gently into the sourdough batter without knocking out the air.
The finished cake is soft, delicate, lightly sweet, and pleasantly flavored with vanilla and sourdough.
Whether you’re looking for a new sourdough discard recipe or simply want a light homemade cake for the weekend, this recipe is easy to adapt and enjoyable with almost any topping.
Keep it simple with powdered sugar, add fresh berries for a fresh finish, or serve it with whipped cream when you want something a little more special.
