Really light sponge cake
I've seen recipes that uses cake flour, AP flour. I've seen recipes using equal parts of eggs, more yolk or more white. As well beating egg whites and yolks together or separately, in part or in whole. And then some use baking powder for additional leavening.
The technique of beating eggs is usually under-explained. How hard (mixer speed), how long to reach maximal air saturation? Tricks to avoid deflation?
What's your experience? What recipe would you recommend?