Kasutera カステラ Japanese Sponge Cake (a.k.a Castella Sponge Cake)

Castella (カステラ Kasutera) is a popular Japanese sponge cake made from 4 basic ingredients - sugar, eggs, bread flour and honey.   It is a speciality of Nagasaki.  The Portuguese merchants introduced this cake to Japan in the 16th century, and the name was derived from Portuguese Pão de Castela, meaning "bread from Castile".   

Basically, the key to success in making this cake is on the eggs, be sure to beat the eggs until it is thick and pale golden in colour, and the batter falls back in ribbon-like when the whisk is lifted!

Anyway, this cake should traditionally be baked in a wooden cake mould, which helps the cake to bake evenly. But I reckon that not everyone has one, so I tried it on a loaf tin instead (at a lower temperature).  The only difference from the loaf tin is that the side of the cake will be browned.  But you can just trim off the sides before serving, and you'll have a nice looking Kasutera! :)

The one I made had a cracked top because of the temperature (baked at 160C), so I amended the temperature in the recipe.  Next time, I'll put in a bowl of water to bake together, to prevent cracks :)  

This recipe was adapted and modified from Anncoo Journal.

Ingredients:
4 large eggs - room temperature
80g caster sugar
50g honey
75g warm milk - microwave for 30 seconds
10g cake emulsifier (Sponge gel)
150g bread flour
a pinch of salt
50g Melted Butter
10g Mirin (*optional)


Method:

1. Preheat oven to 150C.
2. Line the bottom and sides of the loaf tin with parchment paper.
3. Sieve bread flour, plain flour and salt together twice.  Set aside.
   
4. Add warm milk, honey and sponge gel in a small bowl, using a hand whisk, stir until the mixture is smooth. (If you have difficulties dissolving the sponge gel, you may sieve the mixture).  Set aside.
5. Whisk eggs and sugar on medium speed, until batter is thick and creamy white.
6. Turn to low speed, slowly add in the milk mixture and mix well.
7. Then add in flour bit by bit (about one tablespoon at a time) until well combined.
8. Lastly fold in melted butter and mirin in two portions and mix well.
9. Pour batter into the baking tin, tap on table top few times to release air bubbles, and bake for 50-60 mins or skewer inserted comes out clean.
10. Once done, remove the cake from the oven and let it rest for a while.   Then cover the top with a parchment paper, and invert the cake to remove the baking tin.
11. Let the cake cool down slightly, say 15min (the cake should feels warm and is manageable by hand).   Wrap it up with cling wrap, then parchment paper. Store the warm cake in the refrigerator overnight (at least 12hrs).
12. Trim the sides of the cake before serving.

Note: Chilling the cake overnight will ensure a moist texture.  Cooling in room temperature will gives you a 'dry' Kasutera. 

Lined all sides of the tin.

The milk solution, sieved.

Eggs should be whipped until it is really creamy, and pale golden colour.  

All wrapped to be sent for overnight chilling!

All chilled up!

Trim off the sides.

Yum yum!