Whisk egg yolks and sugar (a) into a sabayon for around 15 to 20 minutes, until it reaches ribbon stage.
Whisk egg whites and sugar (b) into a meringue until medium peak.
Fold the sabayon, meringue, and dry ingredients together. Then, take a portion of the mixture and mix it with the warm melted butter.
Fold the butter mixture back into the main batter, then spread onto a baking tray.
Fold the butter mixture back into the main batter, then spread onto a baking tray.