# Mix softened butter, thinly grated kasar cheese
and egg white in a deep bowl by a fork until it turns into homogenous.
# Add very thinly chopped uncooked spinach
, salt, the mixture of baking powder with some flour
and mix it for a while more.
# Knead the mixture by adding flour
in it little by little. Make the dough stop sticking to your hands. Then rest it for about 10 minutes.
# Pick walnut
sized pieces from the dough. Shape them over the bench as pencils.
# Fold the dough bar from the middle and twist it around itself for 2 times.
# Transfer the cookies into a greased baking tray. Spread yolk all over and sprinkle nigella.
# Place the tray into the oven which is preheated to 390 F. Bake them until they turn into red.