Definitely should use this recipe (taken RTHK DIY site) to practice the technique for making sponge cake.  As your skill improve, you could start reducing the special chemical agent “SP” to see if you maintain the same texture and consistency by your own technique.  The one I really like about this sponge cake is that it is really not over powering sweet.
  • 2 eggs (whole egg method)
  • 7 g of SP (sponge emulsifier)
  • 48 g of sugar
  • 48 g of pastry flour
  • 20 g butter

Preheat oven to 180c/350F.  Measure butter in a tiny bowl and set that bowl on a bigger bowl of hot water to gently melt butter.  Once melted, set aside to be use later.

The step is very simple.  Basically dump everything except the flour into a medium mixing bowl and beat for 5 mins (or until the batter reach firm meringue like consistency.)  Sift in the flour in 3 addition and fold into batter.  Finally take a blob of batter and mix into melted butter (folder/stir) until mixed and finally fold the butter mixture into cake batter.

Pour batter into 6″ parchment paper prepared pan bake for 30 mins.  (I start checking in 25 to see if that’s done)