Cut the olives into rings. Mix the flour with the olives, rosemary, salt and pepper, baking powder and baking soda. Cut 150 g feta into cubes (use one cube per muffin), cut the remaining feta into small pieces.
Beat the egg lightly. Mix well with the oil and yoghurt. Add the flour mixture and stir briefly.
Pour half of the batter into the wells of a 12-cup muffin tin. Put 1 cheese cube on each. Top up with the rest of the batter and sprinkle with the rest of the cheese.
Bake in the oven preheated to 180 ° C for 25 - 30 minutes. Remove from the oven, let stand for 5 minutes and then remove from the mold.