Spray an 8 or 9 inch square baking pan with nonstick cooking spray. Place two pieces of parchment paper, each approximately 9 inches long and 6 ½ inches wide crisscross in the pan so that the ends extend on all 4 sides. Secure with metal clips, if desired.
Spray the parchment paper with nonstick cooking spray. Set aside.
Place butter, oil and chocolate chips in a heatproof bowl. Fill a small saucepan with approximately 2 inches of water and bring to a boil.
Remove pan from heat and place bowl of chocolate, butter and oil mixture on top forming a double boiler. Do not allow the bottom of the bowl to touch the hot water. Allow the mixture to melt completely, stirring occasionally.
In a large mixing bowl, whisk together both sugars and eggs vigorously for several minutes until sugar dissolves.
In a medium mixing bowl, whisk together the flour, cocoa powder and salt until well blended.
Pour melted chocolate, butter and oil mixture into sugar and eggs and whisk well.
Using a rubber spatula, blend dry ingredients into chocolate mixture.
Pour the batter into the prepared pan, spreading it evenly.
Bake brownies for approximately 33-35 minutes or until a small knife inserted into the center comes out almost clean.
Remove clips, if using, and allow the brownie to cool in the pan.
Chill brownie until firm.
Grabbing overlapping parchment paper on either side of the pan, remove brownie and place it on a cutting board. Using a sharp knife, cut into approximately 9 brownies.