How to cook
Put the yeast in a bowl, add the sugar and warm water, stir. Add a little flour, enough to get a sludge.
Cover it and leave the yeast to activate. In a large bowl, mix 1 egg + 1 egg white (leave the yolk for smearing), the yoghurt, soft butter (4/5 cup (200 g)) and salt.
Stir, add the effervescent yeast, stir and gradually add the sifted flour, knead a soft, nonstick dough.
Smear the dough with oil and cover with plastic wrap to keep it fresh. Leave it to rise in a warm area until doubled in volume.
After it's risen a bit, finish kneading and divide the dough into 2 balls. Take 1 ball and roll it out into a sheet 1/8 (4 mm) thick.
Smear it with softened butter, sprinkle generously with the feta cheese and cheese. Roll it up into a roll and cut it into pieces about 2 1/2″ (6 cm) long.
Arrange them in an oiled oven dish with the cuts facing up - pinch them closed so the cheese doesn't spill out. Do the same for the other ball of dough.
Cover loosely with plastic wrap and leave for about 1 hour to rise. Smear with the set aside yolk, mixed with 2 tbsp oil, and bake in a preheated 338°F (170 °C).
After 15-20 min. of baking, sprinkle with the grated cheese and bake to a golden color!