1. Sift flour.
2. Whisk the yolks lightly and add in the wet ingredients followed by flour till well mixed.
3. Beat egg whites till foamy with electric whisk and add in sugar gradually,beat till soft peaks formed.
4. Fold in 1/3 of egg white mixture into yolk mixture. Then slowly fold in the rest until well mixed,do not deflate the egg white mixture.
5. Pour into tin.
6. Bake in a preheated oven at 180°C for 40-42 minutes.
7. Remove from oven and leave on wire rack to cool.
Adapted from: http://dequeenkitchen.blogspot.com/2013/03/yuzu-chiffon.html