Adjust oven rack to upper middle and lower middle positions. Line two baking sheets with parchment. Preheat the oven to 350 (moms recipe 325) degrees F. Combine nuts, flour, and salt in bowl.

Beat butter, ½ cup powdered sugar (I use ⅓c granulated), and vanilla with an electric mixer in a large bowl until light and fluffy, about 3min.

Reduce speed to low and slowly add nut mixture till combined, about 30 sec. Scrape down bowl and continue to mix until dough is cohesive, about 7 sec. Give dough a final stir by hand to ensure no dry pockets remain.

Roll dough into walnut-sized balls and place 2 inches apart onto ungreased baking sheets.

Bake in the preheated oven until bottoms are light golden brown but tops are still pale, 12 to 15 minutes (mom’s recipe says 18min rotating halfway through at 325). I recommend baking 14min at 325F rotating halfway through . (Try not to let cookies get too brown: it's better to undercook them than to overcook them.)

Remove cookies from the oven and let sit on the baking sheets briefly before removing to wire racks. I recommend cooking on baking sheets then rolling in sugar once cooled (usually doesn’t require second roll as below).

Place ⅓ cup powdered sugar in a shallow bowl; roll hot cookies in sugar to coat, then return to the wire racks to cool.

Once cooled, roll cookies in the powdered sugar once more.