👨‍🍳 Instructions

1. 1

   Grease and line an 8-inch round cake pan or steamer with parchment paper.

2. 2

   In a large bowl, beat the eggs with the brown sugar and castor sugar using an electric mixer on high speed for about 5 minutes, or until the mixture is thick, pale, and forms ribbons when the whisk is lifted (ribbon stage).

   ⏱️ 5 minutes

   💡 Tip: Properly beating the eggs is key to the cake's airy texture.
3. 3

   Sift the plain flour, custard powder, baking powder, and baking soda together into a separate bowl. This helps to aerate the dry ingredients.

4. 4

   Gently fold the sifted dry ingredients into the egg mixture in two or three additions, using a spatula. Be careful not to overmix; stop when just combined.

   💡 Tip: Fold gently to maintain the air incorporated in the eggs.
5. 5

   In a small bowl, whisk together the milk, vegetable oil, and vanilla extract (if using). Gradually add this liquid mixture to the batter, folding gently until just combined.

6. 6

   Pour the batter into the prepared cake pan. Tap the pan gently a few times to release any large air bubbles.

   💡 Tip: Releasing large bubbles prevents uneven texture.
7. 7

   Set up your steamer. Fill a large pot or wok with about 2 inches of water and bring to a rolling boil over medium-high heat. Place a rack or steaming stand in the pot.

8. 8

   Carefully place the cake pan onto the rack in the steamer. Cover the pot with a lid. To prevent condensation from dripping onto the cake, wrap the lid in a clean tea towel or slightly ajar the lid.

   💡 Tip: Slightly ajarring the lid or using a tea towel helps manage steam.
9. 9

   Steam for 30-35 minutes, or until a skewer inserted into the center comes out clean. Avoid opening the steamer lid during the first 25 minutes of steaming.

   ⏱️ 35 minutes

   💡 Tip: Resist the urge to peek too early, as this can cause the cake to collapse.
10. 10

    Once steamed, turn off the heat. Let the cake sit in the steamer for 5 minutes before carefully removing the lid and the cake pan. Let the cake cool in the pan for 10 minutes before inverting it onto a wire rack to cool completely.