Preheat the oven to 350 degrees F. Place a heatproof bowl over a saucepan of simmering water, and melt the chopped chocolate and butter. Stir to combine and set aside to cool slightly.
Add the eggs, brow sugar, and granulated sugar to the bowl of an electric mixer fitted with a whisk attachment. Whisk until thick, light and creamy.
Fold in the melted chocolate and butter mixture. Sift in the cocoa powder, smoked sea salt, and baking soda. Fold in the dark chocolate chips.
Drop spoonfuls of the batter onto a baking sheet lined with parchment paper. Sprinkle with additional smoked sea salt. Bake for 8 minutes. Leave on the tray for a few minutes to firm up before transferring to a wire rack.