Dissolve the yeast in the water with the sugar and 2 tbsp flour. Sift the flour, make a well and pour the effervescent yeast in it.
Add the rest of the products and knead a nice, soft dough. Put a coin in the dough. Cover with a towel and let it rise for 20 min.
Knead again, transfer it to an oiled tray and press it firmly to the bottom and sides of the tray. Make the cross and grapes from the dough. Cover with a towel and leave it for 15 min.
Before baking, smear the pita with a mixture of oil, flour and salt. Bake at 356°F (180 °C) for 35-40 min.