Scoop out heaping teaspoons of dough, then roll them into balls between your hands. Place on a cookie sheet and bake for 13 minutes. Remove from the oven and keep on the cookie sheet for 3 to 4 minutes. Remove from the pan with a spatula and allow to cool completely before icing.
04To make the icing, combine 1 egg white with the rest of the icing ingredients. Whisk thoroughly until combined, adding either more powdered sugar or more juice until it reaches a pourable but still thick consistency.
05Drizzle the icing across the cookies in several lines, then do it again in the other direction. Sprinkle with extra zest before the icing sets.