Preheat your oven to 350°F (175°C). Line an 7 or 8 inch square baking pan with parchment paper and set aside.
In a large mixing bowl, combine the melted hot butter and oil. Add the granulated sugar and whisk until well combined.
Add the eggs and vanilla extract. Beat about a minutes after adding eggs.
Add the flour, cocoa powder, and salt to the wet mixture, stirring until just combined. Be careful not to overmix.
Add espresso powder and chocolate chips (optional).
Pour the batter into the prepared baking pan and spread it evenly. Bake in the preheated oven for 18-20 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
Allow the brownies to cool completely in the pan before slicing into squares.