Preheat oven to 350° F. Spray a 13 x 9 x 2” baking pan with nonstick cooking spray. Line the pan with foil that hangs over 2 sides of the pan. Spray again with nonstick cooking spray.
Whisk flours, baking powder, salt and baking soda in a medium bowl.
Melt butter in a large saucepan over low heat. Remove the saucepan from heat.
Add the sugar to the butter, and whisk to blend. Whisk in eggs and vanilla extract.
Pour the butter mixture into the flour mixture and blend well using a rubber spatula. Spread batter into prepared pan. Sprinkle with chocolate chips and pecans. Bake Blondies until a small sharp knife inserted into the center comes out with moist crumbs attached, about 25 minutes. Cool in pan.