Homemade Brownies

Bahan-bahan (16 porsi)

• ½ cup butter (melted)
• 2 tablespoons vegetable oil
• 1⅓ cups granulated sugar
• ⅔ cup unsweetened cocoa powder
• 2 large eggs (room temperature)
• 1 teaspoon vanilla extract
• 1 teaspoon espresso powder (or instant coffee)
• ½ teaspoon salt
• ½ cup all-purpose flour
• 1 cup semi-sweet chocolate chips (plus more for topping)