Cotton Soft Chocolate Sponge Cake

February 19, 2022 by Catherine Zhang 42 Comments

Soft, fluffy, and jiggly souffle-like cake with a deep cocoa flavor, with a cotton soft texture this chocolate sponge cake is to die for!

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Ingredients
How to make a chocolate souffle sponge cake (with pictures)
Creating the perfect souffle sponge cake
Troubleshooting
More tips
Serving Suggestions
📖 Recipe
💬 Comments

I recently uploaded my souffle castella cake and it was so loved by all of you that I thought you would love a chocolate cake version as well! This cake is so soft and spongy, and when enjoyed warm out of the oven tastes like taking a bite out of a warm and fluffy chocolate cloud.

Cotton soft chocolate sponge castella cake

Ingredients

Whole milk: Provides moisture, richness, and contributes to the tenderness and smoothness of the batter.
Unsalted butter: Adds fat, enriching flavor, tenderizing the crumb, and helping with the cake’s structure and texture.
All-purpose flour: Provides structure and body, forming gluten that helps the cake rise and hold its shape.

Unsweetened cocoa powder: Adds chocolate flavor, color, and slightly reduces the gluten formation for a tender crumb.
Egg yolks: Add richness, color, flavor, and contribute to a smooth batter and overall richness.
Vanilla extract: Adds flavor and enhances the cake’s taste and aroma.
Egg whites: Provide structure and volume, creating a light, airy texture by incorporating air into the batter.

White sugar: Adds sweetness, stabilizes whipped egg whites, and creates a stable meringue for structure and rise.
Pinch of salt: Enhances the overall flavor by balancing sweetness and intensifying the chocolate taste.

How to make a chocolate souffle sponge cake (with pictures)

Preheat the oven to 140C and line an 8 x 8 inch / 20 x 20cm square cake tin with parchment paper
Combine the milk and butter in a small saucepan over medium heat and heat until the butter has melted and the milk is just steaming
Sift the flour, cocoa powder, and salt into a large bowl and pour over the hot milk and butter, mix until combined
Add the egg yolks and vanilla extract, and mix until smooth and well combined

how to make chocolate souffle sponge cake

In the bowl of a stand mixer fitted with a whisk attachment add the egg whites and whisk until foamy
Add the sugar and beat on medium-low until the meringue reaches soft to medium peaks
Add ⅓ of the meringue to the yolk mixture and mix until well combined
Add the lightened yolk mixture to the remaining meringue and gently use a whisk to fold the mixture until just combined

Transfer the batter to the lined tin and place it in a larger baking tray filled with hot, but not boiling, water
Bake for 75 minutes or until the cake springs back when touched
Cool on a wire rack for 5 mins
Enjoy warm and serve with a dollop of whipped cream

Creating the perfect souffle sponge cake

While this cake might look simple, it's the small steps and details that can trip you up. Follow these steps for the perfect cake!

Heat the milk and butter until just melted

Heating the milk and butter is one of the tricks to achieving a cotton soft sponge cake. This technique is called the 'cooked dough' method, and essentially breaks down the proteins in the flour so that less gluten is formed, creating a soft sponge.

However, when heating the milk and butter keep a close eye on it so it doesn't overheat. If the milk and butter is too hot it can overcook the dough, causing it to form a sticky paste. The butter should have just melted and the milk should be just steaming.

Use chilled eggs

Chilled eggs whip up to create a firmer, more stable meringue. The meringue forms the base of this cake, helping it rise while giving it it's fluffy texture, so it is essential to have a strong foundation. You can also add a pinch of cream of tartar to your egg whites once foamy to help strengthen the meringue.

Whip the egg whites to soft peaks

One of the most important tips to creating a crack free sponge cake is only whipping the egg whites to soft peaks. If the meringue is whipped to stiff peaks it can cause the cake to rise rapidly while baking, increasing the possibility of the top splitting.

Add the sugar when the egg whites are just foamy, and whip until a dense meringue

While the egg whites should be whipped to soft peaks it is important to ensure that the soft peaks are dense and stable. The best way to create a stable meringue is to add the sugar as soon as the egg whites are foamy and beat the egg whites on medium-low for a longer period of time. This gives time for the sugar to dissolve, and the proteins in the egg whites to form a stronger network. When you look at the meringue the air bubbles should be fine and the surface should be shiny.

Bake the cake in a hot water bath

Baking the cake in a hot water bath helps to even out the oven temperature and create the perfect moist environment for the cake to bake. It is important to even out the oven temperature, as fluctuations in heat can cause the sponge cake to crack. Extra moisture also prevents the surface of the cake from drying out and becoming more susceptible to splitting.

Make sure the water you use in the hot water bath is hot, but not boiling. Boiling water evaporates quicker and could leave your cake dry halfway through the baking process.

Troubleshooting

Cracked cake

There are a couple of reasons why your cake might crack. The biggest offender is an unstable meringue. The meringue is the structure behind the cake, and without it, the cake won't rise or have that souffle-like texture. There are a couple of tips that will help you achieve that strong meringue:

Use a clean bowl: A clean bowl wiped down with vinegar or lemon juice will ensure that your egg whites whip up well
Use chilled eggs: Chilled eggs whip up a lot easier than room temperature eggs

Add the sugar as soon as the egg whites are foamy: Add your egg whites earlier in the meringue whipping process, this gives the sugar more time to dissolve into the meringue and form a dense network with the egg white proteins
Beat on medium low: Beating on medium-low is one of the most important tips to a strong meringue. If you beat the meringue on a high speed you will form large air bubbles, rather small bubbles to form a fine network. While this will take longer you will have a much stronger meringue

While the meringue has to be strong it is also important that you don't beat it to stiff peaks. Stiff peaks rise rapidly in the oven, causing cracks to form. Beating the egg whites to something in between soft and medium peaks is perfect.

Cake didn't rise

The meringue is also the reason why your cake may not have risen. If you haven't whipped up a stable meringue, or it hasn't been whipped enough your cake may not rise as much during the bake. Follow the same tips as above to create a cake that rises up to a perfect souffle texture.

Cake deflated

This cake will deflate a little as it cools, however it shouldn't deflate excessively. There are a couple of reasons why your cake may have deflated.

The meringue wasn't stable: If the meringue isn't stable it won't be able to support the cake out of the oven
The meringue was overwhipped: If the meringue is overwhipped it will rise a lot in the oven, but deflate once it comes out
The cake was underbaked: The cake needs time to set its structure as it bakes. If taken out too early it isn't strong enough to support itself and will deflate

A tip to prevent your cake from sinking excessively is giving it a sharp tap on your counter top right out of the oven. This releases any trapped air that would cause the cake to deflate as it cools. Make sure you don't tap too hard that the cake collapses though!

More tips

I've given you heaps of tips on this blog post to perfect your chocolate souffle cake, but if you need more there are some on the original souffle castella blog post here! While a lot are the same there are still some bits and pieces that could help.

Serving Suggestions

Spread with chocolate ganache: Enhance the cake's rich chocolate flavor by spreading a smooth layer of chocolate ganache on top.
Layer with chocolate buttercream or frosting: Cut the cake into layers and spread each cake layer with buttercream for a delicious, creamy texture contrast.

Serve hot with fresh whipped cream and fruits: Serve warm slices with a dollop of fresh whipped cream and a side of fresh berries or other fruits for a light, refreshing touch.
Dust with powdered sugar: Simply dust the top with powdered sugar for an elegant, minimalist presentation.
Accompany with ice cream: Serve with a scoop of vanilla or coffee ice cream for a delightful hot and cold contrast.

Let's Get Cooking

If you liked this recipe make sure to leave me a comment and rating down below, I would love to know how you went. Also don't forget to tag me on Instagram @catherine.desserts so I can see and share your desserts.

Follow me on facebook, pinterest, youtube and tiktok for more of my baking creations and updates! Until next time... happy caking!

Cotton Soft Chocolate Sponge Cake

Ingredients

How to make a chocolate souffle sponge cake (with pictures)

Creating the perfect souffle sponge cake