Oh heaven help me that's a good brownie!
This recipe is described in the book as follows:
'It is brownie as fetish. The Sweet & Salty Brownie is the Baked brownie in extreme, a decadence on par with other, more well known (and perhaps more respected) desserts...The caramel taste is more of a hint and less of an explosion, befitting this elegant dessert; the result is a fudgey-chocolatey-caramely brownie.'
For the brownie :
1 1/4 cups all-purpose flour
1 teaspoon salt
2 tablespoons dark unsweetened cocoa powder (like Valrhona)
11 ounces (311g) good quality dark chocolate, coarsely chopped
1/2 cup firmly packed light brown sugar
5 large eggs, at room temperature
2 teaspoons vanilla extract
For the filling :
In a medium saucepan, combine the sugar and corn syrup with 1/4 cup water, stirring them together carefully so you don’t splash the sides of the pan. Cook over high heat until an instant-read thermometer reads 350F (175 C), or until the mixture is dark amber in colour, 6 to 8 minutes. Remove from the heat, and slowly add the cream (careful, it will bubble up) and then the fleur de sel. Whisk in the sour cream. Set aside to cool.
For the brownie :
Preheat the oven to 350F (175′C).
Butter the sides and bottom of a glass or light coloured metal 9 x 13 inch pan. Line the bottom with a sheet of parchment paper, and butter the parchment.
In a medium bowl, whisk together the flour, salt and cocoa powder.
Place the chocolate and butter in the bowl of the double boiler set over a pan of simmering water, and stir occasionally until the chocolate and butter are completely melted and combined. Turn off the heat, but keep the bowl over the water of the double boiler, and add both sugars. Whisk until completely combined and remove the bowl from the pan. The mixture should be at room temperature.
Add three eggs to the chocolate mixture and whisk until just combined. Add the remaining eggs and whisk until just combined. Add the vanilla and stir until combined. Do not over beat the batter at this stage, or your brownies will be cakey.
Sprinkle the flour mixture over the chocolate. Using a spatula, fold the dry ingredients into the wet ingredients until there is a just a trace amount of the flour mixture visible.
To assemble the brownie :
Pour half of the brownie mixture into the pan and smooth the top with a spatula. Drizzle about 3/4 cup of the caramel sauce over the brownie layer in a zigzag pattern, taking care to make sure the caramel does not come in contact with the edges of the pan or it will burn. Use your offset spatula to spread the caramel evenly across the brownie layer. In heaping spoonfuls, scoop the rest of the brownie batter over the caramel layer. Smooth the brownie batter gently to cover the caramel layer.
Bake the brownies for 30 minutes, rotating the pan halfway through the baking time, and check to make sure the brownies are completely done by sticking a toothpick into the center of the pan. The brownies are done when the toothpick comes out with a few moist crumbs.
Remove the brownies from the oven and sprinkle with an extra 1 1/2 teaspoons fleur de sel and 1 teaspoon coarse sugar.
Cool the brownies completely before cutting and serving.