Savoy biscuits

8 egg yolks
250 g sugar
125 g flour
60 g cornstarch
8 egg whites
Time: 40 min

Clarify the eggs one by one. Whisk the egg yolks and sugar until pale and foamy. Sift the flour and cornstarch on top of the mixture. Whisk thoroughly. Beat the egg whites until stiff. Combine 1/4 of the whites, whisking vigorously to stretch the dough and combine the rest gently with a wooden spatula. Butter and flour a baking pan. Fill up the pan and put in the oven at 180 C or 356 F for 20 minutes. When baking is finished, check if it is so by dipping a knife into the cake. The blade should come out dry. Unmold immediately on a rack and leave to cool.