Preheat oven to 180°C/350°F
Melt dark chocolate, then add vegetable oil once chocolate is melted. Mix well.
Add in the sugars, vanilla extract, and salt. Whisk until there are no more lumps.
Add the eggs and whisk until incorporated. Mixture should have thickened up by the time the eggs are fully incorporated.
Sift in flour and cocoa powder, then with a spatula, mix well but do not overwork the batter.
Pour batter into a baking tin and bang the tin against your counter a couple times to prevent cracked brownies. During this step, you can add whatever toppings you'd like.
Bake brownie for 20 minutes or until you've reached your desired result. Let it cool completely before cutting into them.