Preheat your oven to 350°F.

Prepare an 8-inch square baking pan by lightly greasing with oil and lining with parchment paper.

In a medium-sized bowl, whisk together the hot melted butter, oil, and sugar for about one minute.

Add the eggs and vanilla extract to the bowl and beat until the mixture is lighter in color, approximately one minute.

Sift the flour, cocoa powder, and salt into the wet ingredients, folding gently until just combined to avoid overmixing.

Transfer the batter into the prepared pan, smoothing the top evenly.

Bake in the preheated oven for 20-25 minutes. The brownies are done when the center is set but still slightly jiggly.

Allow the brownies to cool to room temperature in the pan before cutting into 16 pieces.