Preheat the oven to 200c.
Place the sifted flour in a large bowl and make a well in the centre.
Pour the oil into the well, add the butter, yeast, baking powder, sugar, salt and the spices (if you use the spices) and stir together well until a dough is formed.
Add the water gradually while stirring until the dough is smooth.
Knead for a couple of minutes.
Line a baking sheet with baking parchment.
Pinch pieces of the dough into small balls, about 25g each.
On a clean surface, roll the balls into long snakes, around 1cm thick and 12-13cm long.
Form each snake into a closed ring and arrange on the baking sheet spaced about 2cm apart.
Brush each ring with the whisked egg and sprinkle lightly with sesame seeds (and/or Za'atar).
Leave to prove for 30 minutes.
Bake the biscuits in the oven for 20-22 minutes, until golden brown.
Allow to cool down before storing them in a clean jar or an airtight container.