Oh my God! These are the best cookies. If you love pecans then you got to make them.
2 sticks (1 cup) unsalted butter, softened
3 cups confectioners sugar
1 teaspoon vanilla
2 1/4 cups all-purpose flour
3/4 cup very finely chopped pecans (2 1/2 oz)
3/4 teaspoon salt
Beat together butter and 1/2 cup confectioners sugar in a large bowl with an electric mixer at moderately high speed until pale and fluffy, about 4 minutes. Beat in vanilla, then add flour, pecans, and salt and mix at low speed until just combined. Chill, covered, at least 6 hours.
Preheat oven to 375°F.
Let dough stand at room temperature until just pliable, about 15 minutes. Roll level teaspoons of dough into 3/4-inch balls and arrange about 2 inches apart on lightly buttered large baking sheets.
Sift remaining 2 1/2 cups confectioners sugar into a large shallow bowl.
Bake in batches in middle of oven until bottoms are pale golden, 8 to 10 minutes. Immediately transfer hot cookies to confectioners sugar, gently rolling to coat well, then transfer to a rack to cool completely.
Roll cookies in confectioners sugar again when cooled.
Cooks' note: Cookies keep in an airtight container at room temperature 3 weeks.
Makes about 6 dozen cookies. Active time: 30 minutes. Start to finish 7 1/2 hours (includes chilling)