Cream butter until creamy. Fold in powdered sugar. Fold in half of the orange zest, orange juice and as much flour as possible. Knead in remaining flour.
Form small balls (approx. 2 cm ø) from the dough little by little and place them on a baking tray lined with parchment paper. Bake at 160- 170 °C on middle rack for 15-18 min. Cool for 3-5 min.
3. mix sugar and remaining orange peel in electric mixer. Roll orange snowballs in it while still warm. Cool.