Sweet and Salty Brownies

INGREDIENTS

• :
• 1 cup granulated sugar
• 2 tablespoons light corn syrup
• ½ cup heavy cream
• 1 teaspoon fleur de sel
• ¼ cup sour cream
• 1¼ cups all-purpose flour
• 1 teaspoon table salt
• 2 tablespoons dark unsweetened cocoa powder
• 11 ounces dark chocolate, coarsely chopped
• 1 cup unsalted butter, cut into 1-inch cubes
• 1½ cups granulated sugar
• ½ cup light brown sugar
• 5 eggs, at room temperature
• 2 teaspoons vanilla extract
• 1½ teaspoons fleur de sel
• 1 teaspoon coarse sugar