Step 1

Preheat the oven to 350ºF. Melt the butter in a large bowl (or in a saucepot and then transfer to a bowl).

Step 2

Add the cooking oil and cocoa powder to the melted butter and whisk until smooth.

Step 3

Whisk the sugar into the chocolate mixture until evenly incorporated, then whisk in the eggs, vanilla extract, and salt.

Step 4

Stir in the flour until it forms a thick batter. Finally, fold in the chocolate chips.

Step 5

Prepare an 8x8-inch baking dish by coating it with butter or non-stick spray, then laying in a piece of parchment paper (the paper does not need to cover all sides of the dish). Add the brownie batter to the prepared dish, then spread it out evenly.

Step 6

Bake the brownies in the preheated oven for 40 minutes. The brownies will be quite soft and moist, even when fully baked.

Step 7

Remove the brownies from the oven and let them cool for 10 minutes before lifting them out of the baking dish. Slice into nine pieces and serve.