Preheat oven to 350 degrees F. Line a 9 inch square metal pan with foil and spray foil with cooking spray.
Sift together flour, cocoa powder and salt. Set aside.
Melt chocolate in top of a double boiler or melt in a metal bowl set over (but not touching) a saucepan of barely simmering water.
Beat butter and both sugars in a large mixing bowl using high speed of an electric mixer. Beat in vanilla and golden syrup. When creamy, beat in eggs, beating thoroughly after each egg.
Beat in the melted chocolate, scraping sides of bowl.
Add flour mixture and chocolate chips, stirring until flour is blended in (do not beat).
Pour batter into prepared pan and bake on center rack of oven for 35 minute or until brownies appear set. Cool on a rack for 1 hour or until brownies are cool enough to transfer to the refrigerator. Transfer to the refrigerator and chill for 1 or 2 hours.
Lift brownies from pan by grasping foil. Place on a cookie sheet and cut into squares.