Gluten Free Castella Cake (カステラ)
Updated: Jan 21, 2021
Castella cake is a famous dessert from Japan. I was first introduced to it in a small gluten free cake shop in Asakusu, Tokyo call Otaco. It is a extremely light sponge cake that can be subtly flavoured by a variety of things like matcha, rose, sakura, chocolate or strawberry. But by far the best thing about this cake is the texture. When it's cooked correctly, it is the softest and airiest cake. It should have a soft brown crust on top but have no crust on the sides or bottom. Check out my recipe video below for how to make two variations of this Japanese dessert.
How do I bake this?
This cake requires a special cooking technique to make sure that it doesn't brown on the sides and the bottom. You will need two baking tins, one slightly bigger than the other, and a deep dish baking tray. This will be filled up with water so the cake bakes evenly throughout, while keeping the oven moist so it doesn't dry out and crack. It is a similar technique that you use when baking some cheesecakes and custards.
Why did my cake sink?
It's important to note that the cake will sink a little after it comes out of the oven, but it shouldn't sink in the centre. If it has this may be because you have taken it out of the oven slightly too early. It can be easy to think that the cake is ready before it actually is because of the lovely brown crust that will form at about 40 minutes, but don't be fooled - leave it in there! The top shouldn't burn before 80 mins because the temperature is low. If you are worried that it is burning/your oven has trouble regulating temperature, lower the heat to. 120°.
I have also included a variation of this recipe with matcha swirled throughout the cake. Please note that you could do this with other flavours as well. If you wanted the whole castellated cake to be matcha flavoured, just double the amount of matcha and mix it in at step 8.
I N G R E D I E N T S
1/4 teaspoon salt
60 grams of butter
100 mls of milk
60 grams of gluten free flour
20 grams of corn flour
1/4 teaspoon of xanthan gum
90 grams of caster sugar
1/2 teaspoon of matcha (optional)
M E T H O D
Preheat oven to 150° celsius.
Seperate 5 eggs into whites and yolks, add the 6th egg to the yolks bowl
Melt 60 grams of butter and 100ml of milk in a bowl over hot water until combined.
Remove from heat.
Sift 60 grams of gluten free flour, 20 grams of cornflour, 1/4 teaspoon of xanthan gum to the butter and milk.
To the butter and milk mixture, mix in one egg yolk at a time until they are all combined.
Whip the egg whites, when they begin to whiten slowly add the sugar and salt. Whip until soft peaks have formed.
Fold the egg white mixture slowly into the butter mixture until all combined.
Line a 9 by 9 inch cake tin with baking paper. Try to cut the paper so it sits in the tin without creasing.
Slowly pour the cake mixture into the cake tin. Bang the tin several times to get rid of the bubbles.
Put the cake tin into a larger tin and place both tins into a deep oven tray.
Place tray in oven and then add water to the baking tray.
Bake for 70 minutes
Immediately remove from tin.
Wait until its cooled before cutting
If you would like to make the matcha variation, complete steps up until 8 and then continue below:
Split the mixture into 2 bowls
Add 1/2 tablespoon of matcha into on bowl and fold (don't overmix). Don't worry if the matcha still has small lumps.
Alternate pouring both mixtures into prepared tins.
Continue on with step 11.