It is
essential to beat eggs until foamy when making an airy light sponge cake.
When baked, the air in the bubbles expands and gives a fine texture to
the cake. To beat eggs well you should first bring them to the room
temperature. The eggs and sugar should be eaten until creamy white and
thick. To check whether the egg is well beaten enough, scoop out some of
it and drip it back into the egg mixture, it is good enough if it stands
on the surface briefly.
After beating
the egg mixture and adding in the sieved flour, use a plastic spatula to
stir gently. Scoop the mixture up from bottom to stir while turning the
mixing bowl at the same time. Stir gently until no trace of flour is
seen. Do not over stir it, or lumps will be found in the dough and the
sponge
cake will turn out less smooth.
After adding
in the flour, mix warm melted butter with some of the batter. Pour it
back into the batter and stir quickly. Pour the batter into a baking
tin. Knock the tin gently on the table several times to release the big
bubbles. The sponge cake will have a smooth surface and a fine texture after
baking.