How to make
Put the baking soda to bubble in the yoghurt, along with the flour and 8 tbsp oil. Knead a soft dough.
Divide it into 2, roll out 2 sheets, about 3/4″ (2 cm) thick. Smear 1 sheet with the butter, sprinkle with the crumbled feta cheese and cover with the 2nd sheet.
Roll it up into a roll and leave for 30 min. to sit. Then cut it into 1 1/4″ (3 cm) thick slices and without crushing them, pull them sideways carefully.
Fry the prepared Fatties in heated oil until golden.
Keep in mind that they release their own fat, so you don't need much oil to fry them.
If you're not a fan of frying, you can grill them in a preheated 390°F (200 °C) oven for 25-30 min. instead.