Line a 13 x9 baking pan with parchment paper. Spray sides of pan with non-stick vegetable spray and set aside. In a large bowl, mix together butter and brown sugar. Beat in eggs and vanilla until mixture is smooth.
Stir in flour, baking powder and salt; mix in pecans, chocolate chips and baking bits. Pour into prepared pan and spread evenly. Bake at 375° for 30 to 40 minutes or until set in the middle. Allow to cool in pan before cutting into squares.