Foam Cakes

True spongecakes These cakes are called in French biscuits (meaning twice cooked) because when they were originally made, the egg yolks and sugar were whipped together in a copper bowl nestled in the lukewarm embers of a fire. This procedure started the poaching of the yolks and trapped tiny bubbles of air into the thick foam before the beaten egg whites and the flour were added to finish the batter. The beaters of the electric mixer provide enough friction heat to replace thi