This intriguing bar cookie was shared by my friend Thea Cvijanovich. Her sister Eva Abplanalp, who lives in Kamo-Whangarei, New Zealand, sent the recipe to her. It is a popular New Zealand cookie.
Set a rack in the lowest level of the oven and preheat to 350 degrees.
For the dough, beat the butter with the sugar and salt in an electric mixer fitted with the paddle attachment on medium speed, until soft and light, 2 to 3 minutes.