Preheat oven to 350°F. Line two baking sheets with parchment.
Cream butter with the powdered sugar for the dough until light and fluffy, about 2 minutes.
Mix in vanilla and salt until smooth.
Blend in flour on low just until a soft dough forms; do not overmix.
Fold in chopped pecans. Cover and chill the dough for 20 minutes to firm slightly.
Scoop 1-tablespoon portions, roll into balls, and arrange 1 inch apart on the sheets.
Bake 12–14 minutes, until set and the bottoms are lightly golden.
Cool on the sheet 5 minutes, then gently roll warm cookies in the coating sugar. Transfer to a rack.
Once completely cool, roll each cookie in powdered sugar a second time for a thick, snowy finish.