In large bowl, beat softened butter, granulated sugar and brown sugar with electric mixer on medium speed 2 minutes, scraping bowl occasionally, until fluffy. Beat in eggs, one at a time, just until smooth. Beat in vanilla. On low speed, beat in one-third of the flour mixture, then half of the milk, beating well after each addition, just until smooth. Repeat with flour mixture and milk, ending with flour mixture, scraping side of bowl occasionally. Stir in baking chips and pecans. Spread batter evenly in pan.