8ounces/230 g bittersweet chocolatecoarsely chopped
6ounces1 1/2 sticks/170 g unsalted butter, cubed
1 1/2cups/300 g granulated sugar
4large eggsat room temperature
1teaspoonpure vanilla extract
1cup/120 g all-purpose flour
1/2teaspoonfine-grain sea salt
1cup/130 g walnut pieces
Cream Cheese Layer:
16ounces/450 g cream cheesesoftened
4tablespoons1/2 stick/60 g unsalted butter,softened
3cups/360 g confectioner's sugar
seed of 1 vanilla bean
Semisweet ganache glaze
6ounces/170 g semisweet chocolatefinely chopped
2tablespoons/30 g unsalted butter
1/2cup/120 ml heavy whipping cream
1tablespoonlight corn syrup
Maldon flake sea salt
Instructions
Make the Bittersweet Brownie Layer:
Preheat the oven to 350 degrees F/180 degrees C.
Butter and flour a 13 x 9-inch/33x23 cm baking pan; set aside.
Place the chocolate and butter in a medium saucepan and place the pan over low heat. Stir until the chocolate and butter are melted and well combined. Remove the pan from the heat source and pour the chocolate mixture into a large mixing bowl. Let the mixture stand until it is barely warm to the touch, about 10 minutes.
Stir the sugar into the cooled chocolate mixture with a large wooden spoon. Add the eggs, one at a time, stirring well between each addition. Stir in the vanilla. Add the flour and salt and stir until just combined. Gently fold in the walnuts.
Pour the mixture into the prepared baking pan and smooth evenly with the back of the wooden spoon. Bake for 22 to 25 minutes, or until a toothpick inserted into the center comes out mostly clean with a few moist crumbs clinging to it. Allow the brownies to cool completely in the pan.
Make the Cream Cheese Layer:
Combine the cream cheese, butter, and confectioner's sugar in a large mixing bowl. Beat on low speed with an electric mixer until just combined. Increase the speed to high and beat for 3 minutes, or until the mixture lightens in color. Add the vanilla seeds and beat for 1 minute longer.
Spread the frosting evenly over the brownie layer and chill until firm, about 2 hours.
Make the Semisweet Ganache Glaze:
In a small saucepan, combine the chocolate, butter, and heavy whipping cream. Cook over low heat, stirring slowly and constantly with a whisk, until the mixture is smooth, 5 to 7 minutes. Remove the pan from the heat source and stir in the corn syrup. Let the glaze cool to room temperature, about 25 minutes. Pour the glaze over the set cream cheese layer and use an offset spatula to spread the glaze evenly to the corners of the pan.
Chill the brownies for 3 hours, or overnight. Cut the chilled brownie slab with a sharp knife. Garnish each slice with a 2 finger pinch (meaning, pinch the salt between your thumb and 2 fingers) of Maldon salt; add more to taste. The brownies will keep, well covered, in the refrigerator for 5 days.