Put sifted cake flour into a bowl.
Take cooking oil, and microwave for about 1-2 minutes. The temperature is about /78-85°C. Pour the hot oil into the flour and mix well.
2
Take the condensed milk, and add it to the batter.
Mix well.
3
Beat one egg into the batter first. Mix well.
Add 3 egg yolks to the batter and mix well.
4
Add a few drops of lemon juice to 3 egg whites and whip on medium-high speed first.
5
When large fish-eye bubbles appear, add 1/3 of the sugar.
6
Continue to whip on medium-high speed, and add 1/3 of the sugar when small fish-eye bubbles appear. Continue whipping at medium-high speed.
7
When the texture becomes visible, add the remaining 1/3 of the sugar. Add the cornstarch. Turn to medium-low speed and whip. Whip until straight and sharp, with dry peaks.
8
Take 1/3 of the meringue into the egg yolk and mix well. Then pour the cake batter into the meringue and mix well.
9
Take a 12-cup muffin pan, topped with paper cups. Pour the cake batter into the paper cups, about 80% full. Bake at 260 °F/125 °C for 45 minutes, then bake at 300 °F/150 °C for 10 minutes.