Beat 1 egg and 1 egg white (set aside the yolk for smearing the cookies) with the sugar until whitened. Add the oil and beat again.
Extinguish the baking soda in the yoghurt and add it to the egg mixture. Sift the flour and knead a nonstick dough. Leave it to rest for 10 min.
Roll it out onto a floured surface and cut out shapes, in this case hearts. You can also shape them into walnut-sized balls.
Smear with the set aside yolk beaten with a little milk, sprinkle with sugar and bake at 356°F (180 °C). Enjoy!