Using an electric mixer, beat together the butter and ½ cup powdered sugar until creamy.
Add the salt and vanilla (or almond) extract, and beat until incorporated, scraping down the sides of the bowl as needed.
Add the flour and chopped pecans or walnuts and beat on low speed until combined, scraping down the sides of the bowl as needed.
Chill dough in the refrigerator for at least 2 hours and up to 2 days.
Preheat oven to 350° F. Line baking sheets with parchment paper.
Roll dough into 1-inch balls and place on prepared baking sheets. Bake for 10-12 minutes, until lightly golden on the bottom.
Let cookies cool on the baking sheet for 5 minutes, then roll warm cookies in powdered sugar. Let cookies cool completely and then roll in powdered sugar a second time.
