Preheat the oven to 350°F (175°C) then line a 7x11 inch baking tray with parchment paper and set aside.

In a large bowl combine melted butter, oil and both sugars.

Add the eggs, vanilla and salt then whisk for about one minute until evenly combined and light in color.

Over the same bowl sift in the flour and cocoa powder. Gently fold the dry ingredients into the wet ingredients until JUST combined (do NOT over mix). Fold in half of the chocolate chunks.

Pour the batter into the prepared pan, then smooth the top. Generously top with the remaining chocolate chunks.

Bake for 35-40 minutes, or until the centre of the brownies no longer jiggles and is JUST set to the touch.

Remove from the oven and allow to cool to room temperature before removing from the baking tray and slicing into 16 brownies.