Beat the egg whites until stiff, gradually adding the sugar. Mix flour with cornstarch and baking powder and fold in. Finally add the melted butter and mix everything well.
Grease 1 springform pan or cup cake pan well and sprinkle with the flaked almonds or ground almonds. Pour in the dough and bake on moderate heat (160 to 170 degrees - stick test!) For about 3/4 hour. Do not open the oven door for the first half an hour.
Sprinkle the hot cake with powdered sugar.
Cake pan should have a diameter of 17 cm. Use at least twice the amount of dough for a 28 springform pan. Line the smooth base with parchment paper; Cake attaches very easily!