In a large mixing bowl, whisk together the all-purpose flour, Dutch process cocoa, baking soda, and salt until evenly combined.

In a heatproof bowl, combine the chopped semisweet chocolate and cubed unsalted butter. Place this bowl over a pot of simmering water and stir gently until melted and smooth.

Remove from heat and let it cool slightly before adding the sugars.

Stir in the granulated sugar and light brown sugar until fully combined.

Add the room-temperature eggs one at a time, mixing gently after each addition.

Mix in the vanilla extract until well blended.

Gradually fold the flour mixture into the wet chocolate mixture using a rubber spatula.

Gently fold in the semisweet chocolate chips until evenly distributed.

Cover the cookie dough with plastic wrap and chill it in the refrigerator for at least 30 minutes.

Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

Drop rounded tablespoons of cookie dough onto the prepared baking sheet, leaving space between each ball.

Top each cookie with a few extra chocolate chips and a sprinkle of flaky salt.

Bake in the preheated oven for 10–12 minutes until the edges are set but the center remains soft.

Allow cookies to sit on the baking sheet for about 5 minutes before transferring them to a wire rack to cool completely.