Preheat your oven to 350°F (175°C). Line two large baking sheets with parchment paper and set aside.

In a medium microwave-safe bowl, combine the semisweet chocolate chips and the butter. Microwave in 30-second intervals, stirring between each, until completely melted and smooth. Set aside to cool for about 5 minutes.

In a large mixing bowl, using an electric mixer or a whisk, beat the room temperature eggs, granulated sugar, and brown sugar on high speed for 3-4 minutes. The mixture should become pale, thick, and ribbony. This step is crucial for creating the shiny, crackly tops. Beat in the vanilla extract.

Pour the slightly cooled, melted chocolate mixture into the whipped egg mixture. Gently fold with a rubber spatula until just combined, being careful not to deflate the air you whipped into the eggs.

In a separate small bowl, whisk together the all-purpose flour, cocoa powder, baking powder, and fine sea salt.

Add the dry ingredients to the wet ingredients and fold with the spatula until just combined. Do not overmix; a few streaks of flour are okay.

Immediately drop rounded tablespoons of dough (about 1.5 tbsp or a medium cookie scoop) onto the prepared baking sheets, spacing them about 2 inches apart. The dough will be loose, similar to a thick batter.

Sprinkle the tops of the dough mounds generously with the flaky sea salt.

Bake for 10-12 minutes, or until the edges are set and the tops are shiny and cracked. The centers will still look soft and slightly underdone. This is key for a fudgy interior.

Let the cookies cool on the baking sheets for 10 minutes, as they will be very delicate. They will firm up as they cool. After 10 minutes, carefully transfer them to a wire rack to cool completely.