Heat oven to 350ºF. In large bowl, break up cookie dough. Stir or knead in flour, pecans and vanilla until well blended.
Shape dough into 54 (1-inch) balls. Place 1 inch apart on ungreased cookie sheets.
Bake 10 to 14 minutes or until set but not brown. Remove from cookie sheets. Cool slightly on cooling rack.
Roll warm cookies in powdered sugar; cool on cooling rack. Roll in powdered sugar again.