Set your oven to 350°F (175°C). While it preheats, place a 10-inch cast-iron skillet inside the oven to warm up.

In a mixing bowl, combine the sifted cake flour, Dutch-processed cocoa powder, and Fleur de Sel. Whisk them together thoroughly.

Using a double boiler or microwave, melt the European-style unsalted butter and add the artisanal semisweet chocolate chunks. Stir continuously until the mixture is smooth. Allow it to cool slightly.

In another bowl, whisk the farm-fresh eggs and the organic unrefined cane sugar until they are well combined and slightly fluffy. Add the handcrafted Tahitian vanilla extract and incorporate it into the egg-sugar mixture.

Gently fold the melted chocolate and butter mixture into the egg-sugar mixture until fully incorporated.

Gradually add the dry ingredient mixture (cake flour, cocoa powder, and salt) into the wet mixture. Fold gently until just combined. Do not overmix.

Carefully fold in most of the artisanal semisweet chocolate chunks into the brownie batter, reserving a handful for topping.

Remove the preheated cast-iron skillet from the oven (use caution, it will be hot!) and grease it lightly with butter or cooking spray.

Pour the brownie batter into the hot skillet, spreading it evenly.

Scatter the remaining chocolate chunks over the top of the batter.

Place the skillet back into the preheated oven and bake for 25-30 minutes or until the edges are set but the center is still slightly soft.

Once baked, remove the skillet from the oven and allow the brownies to cool for a few minutes. Serve the brownies warm, topped with a scoop of velvety Madagascar vanilla ice cream if desired.