Prep the nuts. Chop nuts very finely. Aim for small, even pieces, not a paste. Toast them in a dry skillet over medium heat for 4–6 minutes until fragrant. Let cool completely.
Cream the butter and sugar. In a large bowl, beat softened butter and 1/2 cup powdered sugar until smooth, light, and creamy, about 2 minutes. Mix in vanilla.
Add dry ingredients. Whisk flour and salt together. Add to the butter mixture and mix on low just until combined. Fold in the cooled nuts. The dough should feel soft but not sticky.
Chill briefly. Cover and chill the dough for 20–30 minutes. This firms it up so the cookies hold their shape.
Preheat and prepare pans. Heat oven to 350°F (175°C). Line baking sheets with parchment paper.
Portion and roll. Scoop tablespoon-sized portions (about 20–24 grams each). Roll into neat 1-inch balls and space them 2 inches apart on the sheets.
Bake. Bake 12–14 minutes until set and just barely golden on the bottoms. The tops should not brown.
First sugar coat. Let cookies cool on the sheet for 3–4 minutes, then roll gently in powdered sugar while still warm. Place on a rack to cool fully.
Second sugar coat. Once completely cool, roll again in fresh powdered sugar for a thick, even snowy finish.
