Preparation Steps

• Preheat your oven to 350°F (175°C). Grease your 9x13-inch baking pan with cooking spray or line it with parchment paper for easy removal.
• In a medium saucepan, combine 10 oz of semi-sweet chocolate and 16 tablespoons of unsalted butter over low heat. Stir continuously until melted and smooth. Remove from heat and let it cool slightly.
• In a separate bowl, whisk together 1 cup of all-purpose flour, ½ cup of unsweetened cocoa powder, and 1 teaspoon of kosher salt. Set aside.
• In a large mixing bowl, combine 1 cup of sugar and ½ cup of dark brown sugar. Add the 5 large eggs and 2 teaspoons of vanilla extract. Use a whisk or electric mixer to beat until well combined and slightly frothy.
• Pour the melted chocolate and butter mixture into the egg and sugar mixture. Mix until just combined. Gradually add the dry ingredient mixture, stirring gently until no flour streaks remain. Be careful not to overmix!
• Chop the remaining 2 oz of semi-sweet chocolate into small chunks and fold them into the brownie batter, ensuring they are evenly distributed.
• Pour the brownie batter into the prepared baking pan, spreading it evenly. Sprinkle with coarse sea salt if desired. Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.
• Remove the brownies from the oven and allow them to cool in the pan for at least 15 minutes. Lift them out using the parchment paper if used. Let them cool completely on a wire rack before cutting into squares.