The first step is to preheat the oven to 350°F and line a 7×11-inch baking pan with parchment paper. Set aside.
In a large bowl, combine melted butter, oil, brown sugar, and granulated white sugar. Whisk until well combined.
Next, whisk in eggs, vanilla, and salt.
Then, sift in the flour and unsweetened cocoa powder. Gently mix until all is well combined.
Gently fold in the chocolate chunks and chocolate chips using a spatula.
Time to pour that delicious batter into the baking tray! Get ready to bake one of the most delicious brownies.
Bake for roughly 35–40 minutes, until the center of the brownie no longer jiggles.
Allow it to cool at room temperature before taking that amazing, chocolaty first bite.