PREHEAT oven to 350°F. Beat butter and sugars in large bowl with electric mixer on medium speed until light and fluffy. Add sour cream, egg and vanilla; beat until well blended. Add flour, baking powder, baking soda and salt; mix well. Stir in chocolate chips and pecans.
DROP tablespoonfuls of dough, 2 inches apart, onto greased baking sheets.
BAKE 10 to 12 minutes or until golden brown. Cool completely on wire racks.