Step 1: Preheat your oven to 350°F (175°C) and line two large baking sheets with parchment paper or silicone mats.
Step 2: In a large bowl, cream together the softened butter, 1/2 cup of powdered sugar, and vanilla extract until smooth and fluffy.
Step 3: Gradually whisk in the flour and salt until a stiff dough forms. Fold in the finely chopped toasted pecans by hand until evenly distributed.
Step 4: Shape the dough into 1-inch balls (about 1 tablespoon of dough each) and place them 1 inch apart on the prepared baking sheets.
Step 5: Bake for 12 to 15 minutes, or until the bottoms are lightly browned but the tops remain pale. Do not overbake.
Step 6: Let the cookies cool for 3 to 5 minutes on the sheet until they are safe to handle but still warm. Roll each cookie in the extra powdered sugar and place on a wire rack.
Step 7: Once the cookies have cooled completely, roll them in the powdered sugar a second time for a thick, snowy coating.