Cream butter in a baking bowl until soft, add sugar, salt and eggs, stir until pale. Grate lemon peel, add. Add flour, mix to form a dough, chill with lid on for 2 hours.
Shaping: Roll out dough in portions on little flour to 5 mm thickness.
Cut out different shapes, place on a baking tray lined with parchment paper, cool for fifteen minutes, brush with egg yolk. Before baking, draw a fork diagonally over the egg yolk coated Guetzli with light pressure, or make notches with the back of a knife.
Bake: in about ten minutes in the middle of the oven heated to 200 degrees.