Japanese Cotton Sponge Cake (日式棉花蛋糕)

Steps

1. 1

   Preheat your oven to 150°C (300 °F) (300°F (150 °C)). Line the bottom and sides of a 7-inch (18cm) square cake tin with parchment paper, ensuring the paper extends slightly above the rim.

2. 2

   Heat the 60g of corn oil in a small saucepan over medium heat until it reaches approximately 70-80°C (158–176 °F), or until you see small bubbles forming at the bottom. Do not let it boil.

3. 3

   Pour the hot oil into a mixing bowl. Immediately add the 80g of sifted cake flour and whisk until smooth and well combined.

4. 4

   Add the 80ml of milk and whisk until the mixture is incorporated.

5. 5

   Add the 5 egg yolks and 1 whole egg to the flour mixture. Whisk until the batter is smooth, shiny, and free of lumps. Stir in the vanilla extract.

6. 6

   In a separate clean, grease-free bowl, beat the 5 egg whites with the lemon juice until frothy.

7. 7

   Gradually add the 80g of caster sugar in three stages, beating constantly until the meringue reaches firm peaks (stiff but still slightly curved at the tip).

8. 8

   Gently fold one-third of the meringue into the egg yolk batter using a whisk or spatula to lighten the mixture.

9. 9

   Pour the lightened batter back into the remaining meringue. Use a spatula to fold gently using a cut-and-turn motion until no white streaks remain. Do not overmix or you will deflate the air.

10. 10

    Pour the batter into the prepared cake tin. Tap the tin on the counter a few times to release large air bubbles. Smooth the top with a spatula.

11. 11

    Place the cake tin inside a larger baking tray. Fill the larger tray with hot water (about 1-2cm deep) to create a water bath (bain-marie).

12. 12

    Bake in the preheated oven at 150°C (300 °F) (300°F (150 °C)) for 60-70 minutes, or until the top is golden brown and a skewer inserted comes out clean.

    Start 1-hour timer
13. 13

    Remove the cake from the oven and immediately remove it from the tin. Peel off the parchment paper and let it cool on a wire rack to prevent the bottom from becoming soggy.