Judy - Thanks for the explanation on emulsifiers.

Whenever I make a sponge, I would overturn the cake tin when I remove it from the oven to let it cool down. I have been told that this way the cake will not collapse. But on several occassions, I found that the bottom of the cake collapsed! My theroy is that although it is cooked, I should have left it in the oven for a longer time. Does this make any sense??

Wow, Judy, the kueh lapis sure calls for a number of eggs. I will try it out some time and let you know how it goes! Thanks!