Preheat oven to 325 degrees.
Add egg yolk to soft butter and beat for 30 minutes (yes, 30 minutes) until light and fluffy.
Add sugar, nuts and whiskey and mix. Blend in flour a little at a time until dough can be handled without sticking to fingers.
Shape into crescents. Place on greased cookie sheet and bake for 25 minutes until very lightly browned.
Remove from cookie sheet with a table knife and place on waxed paper which has been sprinkled with powdered sugar.
Sift powdered sugar on top of cookies and cool. Makes 60.