1. Heat oven to 350 degree F. Sift together flour, baking soda and salt onto waxed paper. Set aside.
2. Beat together butter, granulated sugar, brown sugar, eggs and vanilla in a large bowl until fluffy. Stir in flour mixture until well blended. Stir in oats and chocolate pieces.
3. Drop batter by rounded tablespoonfuls, 2 inches apart, onto ungreased cookie sheets.
4. Bake at 350 degree F for 10 minutes or until lightly browned. Transfer cookies to wire rack to cool. Note: Our test kitchen recommends a baking time of 20 minutes.