In large mixing bowl, combine butter, sugar and vanilla; using an electric mixer on medium speed, beat until light and fluffy.
Reduce mixer to low; add flour and salt, mixing until well combined, scraping bowl often.
Stir in pecans; chill dough.
Bake in a preheated 375°F oven 10-15 minutes or until set, but not browned. While still warm, roll in powdered sugar; cool completely. Roll in powdered sugar again.