Beat egg whites with a pinch of salt until stiff - turn on the oven to 160 degrees circulating air.
Mix the softened butter with sugar until creamy, mix the flour, almonds, cocoa and flavoring mixed with baking powder, the mixture is now rather crumbly. Now stir in half the amount of the egg white mixture, then slightly fold in the remaining amount of egg white.
Pour the dough into a prepared form (preferably a hop pan) and bake for about 30 minutes (test with chopsticks).