Beat eggs and water until very frothy, about 10 minutes. Gradually add the sugar and stir. Mix the flour, cornstarch and baking powder, sift over the egg mixture and carefully fold in (the more you stir, the more the dough loses air and does not rise so well in the end). Place in a size 26 tin lined with parchment paper.
Bake for approx. 35 - 45 minutes at 175 - 180 ° C top / bottom heat (preheated).
Tip: For a dark sponge cake I add 1 tablespoon. Cocoa to the flour mixture.
The biscuit becomes as high as the 26 cm shape and can be loosely cut twice if necessary.