01 -  In a bowl, blend together flour, sugar, chopped nuts, and orange zest. Cut in the cold butter until the mixture becomes crumbly. 
 02 -  Using your hands, shape the dough into 24 small, evenly-sized balls. 
 03 -  Preheat the oven to 160 °C. Arrange the balls on a baking sheet lined with parchment paper and bake for approximately 15 minutes until pale but set. 
 04 -  Remove the cookies from the oven and allow them to cool slightly. Roll each cookie in powdered sugar twice to ensure a thick coating.