Step 1

Separate 3 eggs into yolks and whites. Place the egg yolks in a small bowl, set aside on countertop. Place the egg whites in a large mixing bowl, keep in the fridge.

Step 2

Add 50g cake flour and 30g vegetable oil into a large mixing bowl, mix with a whisk until smooth.

Step 3

Add 3 egg yolks, 30g milk, and ½ tsp of vanilla extract to the cake flour oil mixture, mix with a whisk until smooth. Set aside.

Step 4

Preheat oven to 300°F (150°C).

Step 5

Take the egg white mixing bowl out from the fridge, add ½ tsp of lemon juice and 15g sugar into the egg whites. Use medium-low speed (speed 2 out of of a hand mixer to whip the egg whites for 2 minutes until fish eye size bubbles form.

Step 6

Add another 15g sugar into the egg whites, use medium-low speed to whip the egg whites for 2 more minutes until the bubbles are too tiny to be seen.

Step 7

Add the remaining 15g sugar into the egg whites, use medium-low speed to whip the egg whites until medium peak forms (*see the pictures in content above for the differences between "soft peaks" and "medium peaks".)

Step 8

Scoop ⅓ of the egg whites into the egg yolk mixture, fold until well combined.

Step 9

Transfer the egg yolk mixture to the egg white bowl, gently fold until the color looks even.

Step 10

Pour the batter into the cake pan, gently spread the batter with a spatula to create a smooth surface. Loosely cover the cake pan with foil.

Step 11

Bake at 300 °F (150 °C) for 20 minutes, then remove the foil. Bake at 300 °F for 35 more minutes.

Step 12

Remove the cake pan from the oven, immediately flip it upside down and allow it to cool completely on a wire rack.

Step 13

To unmold the cake, insert a small knife between the cake and the sides of the cake pan, run it around. Insert four fingers into the gap between the cake and the cake pan, press the cake towards its center, repeat until the bottom of the cake is separated from the cake pan. Flip the cake over onto a serving plate.