Preheat the oven to 180 °C. Cover a baking tray with parchment paper. Knead the butter, flour, sugar, egg yolks and coconut into a dough.
Form 50 balls from the dough, cut them crosswise on the upper side with a sharp kitchen knife and roll them thoroughly in the sesame seeds.
Spread the sesame balls evenly on the baking sheet. Bake in the oven (center, convection oven 160 degrees) for ten minutes.