This is the most important step to do: Cover the lid of the steamer with a kitchen towel to prevent condensation from the lid from falling on to the steamed cake. Fill the steamer with water (below the steaming plate). Cover the steamer with the lid and slowly bring water to boil.
Place the cupcake liners in the molds. Set aside.
Beat together eggs, granulated sugar, and emulsifier with a mixer on a high speed until pale and fluffy (around 10 minutes).
Change to the lowest speed. Add flour and soda water alternately and gradually. Beat again with high speed for about 5 minutes.
Steam for 12 minutes over high-heat. DO NOT open the steamer before 12 minutes.
Remove from the heat. Transfer the steamed cake onto a wire rack. Let it cool. Enjoy!
Note: Save steamed cake in a small plastic storage bag each. It can stay soft and fluffy for couple days.
