Preheat the oven to 320℉ (160℃) and grease or line with parchment paper an 8x8 inch baking pan.
In a big bowl add the oil, eggs, and vanilla extract. Mix for 1 minutes and then add the sugar and mix until combined.
Slowly add the cocoa powder and whisk until it has been absorbed.
Add the flour and salt and mix with spatula or spoon until just compbine
Fold in the chopped dark chocolate or chocolate chips
Pour the brownie batter in the prepared tin and place in the oven. Bake brownies for approximatley 30-35 minutes or until they are no longer wet in the cwnter
Remove the brownies from the oven and allow them to cool in the pan at room temperature until the pan is no longer hot to the touch. For clean lines when slicing the brownies, place them in the frige for about one hour. After they have been in the fridge you can remove them from the baking pan and slice.