Souffle Castella Cake

Name: Taiwanese Souffle Castella
Prep time: 15 min
Cook time: 1 h 15 min
Total time: 1 h 30 min
Cuisine: Taiwanese
Ingredients: 130g Whole milk (1/2 cup 2 tsp); 130g Unsalted butter (1/2 cup 2 tsp); 120g All purpose flour (1 cup); 8 Egg yolks; 1 tsp Vanilla extract; 8 Egg whites; 130g White sugar (2/3 cup)

January 13, 2022 by Catherine Zhang 36 Comments

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The softest and fluffiest wobbly sponge cake. Originating in Taiwan this souffle castella is lightly sweetened with the perfect pillowy texture.

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How to achieve a crack free cake
Frequently Asked Questions
Let's Get Baking
📖 Recipe
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One of the most satisfying things is baking a perfect sponge cake. When the cake is at the perfect height and the surface is perfectly smooth and crack free. This castella is the definition of a perfect sponge cake. You won't find a cake with a better texture than this! The cake itself is light in flavour and slightly sweet, and the texture is light, pillowy and souffle-like.

Originating in Taiwan, these cakes are usually baked as large 1 metre slabs, sliced into large rectangles straight out of the oven, and placed in boxes to be picked up by the long line of customers waiting outside the stores. The popularity of these cakes is never-ending, and there are almost always lines outside the stores.

Taiwanese jiggly souffle castella sponge cake

Although souffle castella was popularised in Taiwan, the original castella is a cake developed in Japan after being introduced by the Portugese. A traditional Japanese sweet made from bread flour, eggs, sugar and mizuame, a type of sugar syrup which gives the cake a moist texture, Japanese castella is a denser and slightly gooier in texture with a darker crust. Instead of being baked on a large scale like the Taiwanese adaptation, Japanese castella is baked in a wooden square or rectangular mould and enjoyed the day after it is baked as it brings out a moister texture.

While both cakes may have the same name they have their own unique charms. I personally love the Taiwanese style because of its fluffy texture, but give this recipe a go and see what you think!

How to achieve a crack free cake

Sponge cakes are the kind of cake that seem relatively simple, but there are so many small areas where things can go wrong. Whether that be a sunken cake or cracked top follow these steps for the perfect castella!

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.

Frequently Asked Questions

Why did my cake crack?

There are a couple of reasons as to why your cake cracked.

The meringue was whipped beyond soft peaks
The meringue wasn't stable enough
The oven temperature was too hot
The water bath used was too hot/ there wasn't enough water in the waterbath

To troubleshoot these errors check out my "how to achieve a crack-free cake" section above!

Why did my cake deflate?

As the name suggests this cake is a souffle castella, and will deflate slightly after cooling, however not enough for it to be a significant problem. If your cake is deflating a lot it could be be due to a couple of factors:

The meringue was overwhipped, causing it to rise more during the bake
The cake was underbaked

How long does this last?

This cake is best enjoyed on the day it's made, but it can last up to 3 days in an airtight container in the fridge. Allow the cake to come to room temperature before consuming if eating from the fridge, or you can toast it in the oven or toaster!

How is this cake best enjoyed?

I personally love this cake when it is fresh out of the oven. At this stage the cake is warm, soft and at its fluffiest. However, when cooled the cake is equally as delicious. Try serving it with some whipped cream and fresh fruit for a delicious all round dessert!

Let's Get Baking

If you are looking for the most satisfying sponge cake look no further! Soft and pillowy sweet perfection.

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 and hashtag #cattycakes 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!

📖 Recipe

Taiwanese Souffle Castella

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★★★★★

5 from 6 reviews

The softest and fluffiest wobbly sponge cake. Originating in Taiwan this souffle castella is lightly sweetened with the perfect pillowy texture.

Author: Catherine Zhang
Prep Time: 15 mins
Cook Time: 75 minutes
Total Time: 1 hour 30 minutes
Yield: 8 x 8 inch cake 1x
Category: Cake
Method: Easy
Cuisine: Taiwanese

Ingredients

Scale

130g Whole milk (½ cup 2 tsp)
130g Unsalted butter (½ cup 2 tsp)
120g All purpose flour (1 cup)
8 Egg yolks
1 tsp Vanilla extract
8 Egg whites
130g White sugar (⅔ cup)

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Instructions

Preheat the oven to 140C
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 into a large bowl and pour over the hot milk and butter, mix until combined
Add the egg yolks and mix until smooth and well combined
In a large bowl 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
Remove from the oven and enjoy warm!

Keywords: cake, sponge cake,. castella, kasutera, taiwanese, jiggly

Souffle Castella Cake

How to achieve a crack free cake