In all Germanic cultures, these are one of the most popular Christmas cookies. This version is from Chur, the gateway city to the Grisons, southeastern Switzerland’s high mountains.
Place the almonds in a food processor fitted with a metal blade. Pulse repeatedly until they are finely ground. Add the cinnamon and lemon zest, pulse twice, then set aside.
In a clean, dry bowl, whip the egg whites with the salt until they’re firm, then gradually whip in the confectioners’ sugar. Remove ⅓