Place cling film on a scale and pinch the corners to stop the ingredients from overflowing. Measure the dry ingredients and set aside.
Pre-heat the oven to 170 degrees Celsius. Start to pre-heat the oven in advance if it takes time. Mix together the cake flour and baking powder.
Separate the egg yolks and whites. Put the egg yolks into a large bowl and egg white into a medium bowl. Do not leave any egg yolk in the whites.
Knock the eggs on a flat surface, not on a sharp corner to keep the egg shells from getting mixed in with the egg. Crack an egg and gently put the yolk into a halved shell.
Add the sugar (40 g) into the egg yolk bowl and beat with a hand mixer at high speed until pale and fluffy.
Add the vegetable oil gradually and then add the milk (or water). Beat well with a hand mixer. Add the vanilla here if you'd like.
Transfer the cake flour and baking powder into a sifter. Remove the cling film from the egg yolk mixture. Sift the flour and baking powder into the egg yolk mixture.
Sift from a high position. I bought this sifter at a 100-yen shop. If you don't have one use any strainer you have.
Beat the mixture with a hand mixer at medium speed until all the ingredients evenly combined.
Beat the egg whites with a hand mixer at high speed. When the egg whites are white and frothy add the rest of the sugar in 2 to 3 batches. Beat at medium to medium-high speed until stiff peaks form.
Beat until the egg whites look like this. For the last 30 seconds beat the egg whites at medium-low to low speed to obtain a smooth finish.
Change your hand mixer to a rubber spatula. Add 1/3 of the egg whites and fold in with a diagonal cutting motion.
With another hand continue to rotate the bowl towards you (like professionals do)! If it is difficultl just move your spatula horizontally and diagonally.
Add the rest of the egg whites in 2 batches and mix as you did at the above steps. When the egg whites have been combined evenly, pour the batter into the chiffon cake mould.
Pour the batter in a stream by holding the bowl 10-cm above the cake moulds. Keep on rotating the moulds so that the batter won't have excess air bubbles. Give the cake moulds several soft taps to remove excess air.
Bake in the pre-heated oven to 170 degrees Celsius for 35 to 40 minutes. A very sweet aroma comes out from the oven!
When a skewer inserted comes out clean it is done. Use your oven mitts when you take out the cake moulds.
Invert the moulds over a glass and cool. The cake will settle slightly.
Run a knife along the centre tube and side of the mould. You can buy a specific knife to do this.
Remove the overflown cake batter because it is tough. (Eat them when no one's looking!)
Push up the cake bottom and remove the cake from the mould. Run a knife between the cake and bottom of the mould and flip over the cake gently.
It is done! Serve with whipped cream or sprinkle with icing sugar. You can decorate the cake with whipped cream and strawberries!
Story Behind this Recipe
I completed my own recipe after many trials. I've showed the process step by step so have a try!
If your hand mixer has only one whisk beat the egg whites first. When you beat the egg yolks next you don't have to wash the mixer. Even a speck of egg yolk will minimise the volume of beaten egg whites. Egg whites in the egg yolks doesn't affect the meringue, though. Use granulated sugar for creating a gentle sweetness.