Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper or a silicone mat.
In a large bowl, beat the room-temperature Unsalted Butter until smooth and creamy, then blend in about half of the Powdered Sugar until light and fluffy.
Mix in the Vanilla Extract until evenly incorporated.
Gradually add the All-Purpose Flour and a pinch of the Fine Salt, mixing just until a soft dough forms; stir in the finely chopped Walnuts by hand so they’re evenly distributed.
Scoop or roll the dough into small 1-inch (2–3 cm) balls and place them about 1 inch apart on the prepared baking sheet.
Bake for 10–12 minutes, or until the edges are set and the bottoms are very lightly golden—avoid overbaking to keep the centers tender.
While still warm (but cool enough to handle), gently roll each cookie in the remaining Powdered Sugar to coat; transfer to a wire rack to cool completely, then roll once more in powdered sugar for a snowy finish.
Store in an airtight container at room temperature for up to a week, or freeze for longer keeping. Serve with tea or coffee.
