Instructions:

• Step 1: Preheat your oven to 350°F (175°C). This ensures that your brownies will bake evenly.
• Step 2: Line an 8x8 inch baking pan with parchment paper, leaving some overhang to make it easier to lift the brownies out later.
• Step 3: In a heatproof bowl, combine the chopped unsweetened chocolate and boiling water. Stir until the chocolate is completely melted and smooth. Set aside to cool slightly.
• Step 4: In a large mixing bowl, combine the melted unsalted butter and vegetable oil. Whisk in the large eggs, egg yolks, and vanilla extract until the mixture is well blended.
• Step 5: Pour the melted chocolate mixture into the wet ingredients and whisk until combined.
• Step 6: In another bowl, whisk together the unsweetened cocoa powder, flour, salt, and granulated sugar until there are no lumps.
• Step 7: Gradually add the dry ingredients to the wet mixture, stirring gently until just combined.
• Step 8: Using a rubber spatula, fold in the semi-sweet chocolate chunks, ensuring they are evenly distributed throughout the batter.
• Step 9: Pour the brownie batter into the prepared baking pan, spreading it evenly. Bake for about 25-30 minutes or until a toothpick inserted into the center comes out with a few moist crumbs.
• Step 10: Remove the brownies from the oven and let them cool in the pan for about 10 minutes. Lift the brownies out of the pan and transfer them to a wire rack to cool completely before slicing into squares.