Step 1: Preheat your oven to 325°F (160°C). Line two baking sheets with parchment paper or silicone mats.
Step 2: In a large mixing bowl, cream together the softened unsalted butter and 1/2 cup of powdered sugar until light and fluffy.
Step 3: Beat in the vanilla extract until well combined.
Step 4: In a separate bowl, whisk together the all-purpose flour and salt. Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined.
Step 5: Fold in the finely chopped pecans (or walnuts) until evenly distributed throughout the dough.
Step 6: Cover the bowl and chill the dough in the refrigerator for at least 30 minutes.
Step 7: Once chilled, roll the dough into 1-inch balls. Place them about 1 inch apart on the prepared baking sheets.
Step 8: Bake for 12-14 minutes, or until the bottoms are lightly golden. The cookies should still be pale on top. Do not overbake.
Step 9: While the cookies are still warm (but cool enough to handle), roll them generously in the remaining 1 cup of powdered sugar.
Step 10: Let the cookies cool completely on a wire rack. Once fully cooled, roll them a second time in powdered sugar for an even thicker, more pristine snowy appearance.