In mixer cream together Sugar, Brown Sugar, Melted Butter, Eggs and Vanilla Extract.
In separate bowl sift together Flour, Baking Powder and Salt.
Slowly add flour mixture to brown sugar mixture then add Semi-sweet Chocolate Chips and Optional Chopped Walnuts or Pecans.
Spread batter into a greased 13" x 9" baking pan. Bake in a 350℉ oven for 20-25 minutes or until inserted toothpick comes out clean. Let cool and cut into bars.