Beat the eggs (at room temperature) with the sugar and add the yoghurt. Mix well and gradually add the flour sifted with the baking soda and softened butter. Slowly knead a soft dough, adding some more flour if needed.
Flour a counter and roll out the dough to a thickness of 1/16. Cut out circles with a small cup, arrange them in a tray covered with baking paper.
Pierce each circle with a straw - make 2 eyes and a 3rd hole for a mouth. Bake the cookies in a preheated 356°F (180 °C) oven for about 12-14 min. - until pink.