I am going to test differnt kind of foam cake recipes in a mission to find the "perfect" foam cake. 

Here is the ingredients:
1/2 cup of cake flour
1/3 cup of sugar
3 large eggs
1 tablespoon of mlik
1 tablespoon of melted butter

Genoise orginal recipe does not need any liquid (i.e. no mlik).  However, I do find the original recipe is too dry (especially when you following 4 eggs, 1 cup of flour proportion).  Straightly speaking this is also not sponge cake because of added the melted butter. I believe melted butter is necessary keep the sponge moist and favourful.  This foam cake is neither or you can say it is the best of both world.

I only use my hand to beat up the foam this time.  Not too bad eh?  In 6" cake pan, it raised to 2.5 inches tall.  I still find the top cake face skin is not nice & brown enough.