Cut the butter into small cubes or grate it and mix all the ingredients with your hands in a bowl.
On a floured surface, make a bun out of the dough and let it cool for an hour or two.
Then transfer the dough onto a floured roll, form a long roll with your hands, cut it into equal pieces and quickly make a half-moon from each one with your hands.
Place the half-moons on a baking sheet lined with baking paper (do not place too close to each other). I baked at 355 °F / 180 C° for about 8-10 minutes (follow your oven - every oven bakes differently).
The half-moons should remain nice and white even after baking - light brown only on the bottom. Let them cool on the baking sheet for a while (they are very fragile after baking) and while they are still warm, roll them in powdered sugar mixed with vanilla sugar.