Set the oven temperature to 225°C. Whisk the egg whites until stiff. Mix the other ingredients together and add to the egg whites, whisking constantly.
Put the batter in a greased cake tin with breadcrumbs or semolina sprinkled inside. Stand the tin in the oven and turn off the heat. Leave in the oven until the cake has cooled completely.
Remove the cake from the tin. Decorate with tinned fruit and chocolate.