In a large mixing bowl, beat together the softened unsalted butter and powdered sugar using an electric mixer until light and fluffy.

Add vanilla extract and salt to the mixture and blend well on low speed until fully combined.

Gradually mix in all-purpose flour until just combined, the dough may appear soft and crumbly.

Fold in the finely chopped pecans or walnuts until evenly distributed.

Cover the dough with plastic wrap and refrigerate for at least 30 minutes.

Once chilled, scoop tablespoon-sized portions and roll them into balls, placing on a prepared baking sheet.

Bake in a preheated oven at 350°F (175°C) for 12 to 14 minutes until lightly golden at the bottom.

Cool cookies on the baking sheet for 5 minutes before rolling them in powdered sugar.

After cooling completely, roll them in powdered sugar again for a sweet finish.