A melt-in-your-mouth cookie that is a Christmas cookie exchange favorite.
Sift the sugar before rolling, so it doesn't clump. The cookie are fragile, so roll them in the sugar gently.
Adapted from Barbara Grunes and Virginia Van Vynckt's "Very Merry Cookie Party: How to Plan and Host a Christmas Cookie Exchange."
*Note: To toast the walnuts, bake them at 350 degrees until they are aromatic and lightly golden, about 8–10 minutes.
Preheat the oven to 350 degrees. Have ready ungreased cookie sheets.
In a large bowl, with an electric mixer, beat together the butter, the ½ cup confectioners' sugar, the cinnamon, and salt on medium speed until smooth and creamy, about 2 minutes. On low speed, gradually beat in the flour and then the nuts just until mixed. The dough will be stiff and somewhat crumbly.
Pinch off pieces of the dough and roll between your palms into 1-inch balls. Place on the cookie sheets, spacing them about 1½ inches apart.
Bake in the center of the oven until the tops are set to the touch and the bottoms are lightly golden, about 10 minutes. Let the cookies cool on the cookie sheets until they are still warm but are firm enough to handle without crumbling.
Spread 1 cup sifted confectioners' sugar on a plate. Roll the warm cookie in the sugar, coating them evenly. Set on wire racks to cool completely. When the cookies have cooled, roll them again lightly in the sugar.