Preheat oven to 325 degrees F. and line a 8x11 inch baking dish with parchment paper sprayed with cooking spray.
Place butter into a large mixing bowl and microwave until partially melted. Add sugar and oil, mix until well combined. Stir in eggs and vanilla stirring until combined then add flour, cocoa powder, salt, baking powder and chocolate chips. Stir until combined and thick.
Transfer batter to prepared baking dish, spreading evenly. Bake for 35-40 minutes, until baked through. Remove and let cool completely, about an hour. Lift parchment and brownies out of pan and cut into squares to serve.