Step 1: Preheat your oven to 375°F (190°C). Line a large baking sheet with parchment paper or a silicone baking mat.
Step 2: In a large bowl, cream together the softened butter, 1/2 cup powdered sugar, and vanilla extract until the mixture is smooth and fluffy.
Step 3: Gradually whisk in the flour and salt on low speed until a soft dough forms. Do not overmix.
Step 4: Fold in the finely chopped pecans or walnuts by hand using a spatula until evenly distributed.
Step 5: Shape the dough into 1-inch balls and place them 2 inches apart on the prepared baking sheet.
Step 6: Bake for 10 to 12 minutes, or until the cookies are set but not browned.
Step 7: Remove from the oven and let cool for 3-5 minutes. While still warm, roll the cookies in a bowl of extra powdered sugar.
Step 8: Allow the cookies to cool completely on a wire rack, then roll them in powdered sugar once more for a thick coating.