Cream butter, the 1/2 cup powdered sugar, and vanilla.
Combine flour, pecans, and salt.
Stir into butter mixture.
Shape dough in 1-inch balls.
Place on ungreased baking sheet.
Bake in 325° oven 20 to 25 minutes till lightly browned.
Roll warm cookies in powdered sugar.
Cool on wire racks, then roll again in powdered sugar.
Sprinkle with additional chopped pecans, if desired.