**Preheat and Prep:** Preheat your oven to 350°F. Line a large 15x21 inch baking sheet with parchment paper and set aside. (You can also use 2 standard baking sheets if needed.)

**Melt Butter and Chocolate:** In a microwave-safe bowl, melt the butter and chopped dark chocolate together. Set aside to cool slightly.

**Mix Dry Ingredients:** In a medium bowl, whisk together the flour, cocoa powder, salt, and baking powder. Set aside.

**Beat Sugars and Eggs:** In a large bowl, add the granulated sugar, light brown sugar, eggs, and vanilla. Beat on high with an electric mixer for at least 7 minutes. This step helps create the crinkly top layer on the cookies.

**Combine Wet and Dry:** Mix in the melted chocolate and butter. Then add the dry ingredients to the wet mixture, stirring until just combined. The dough will be very soft.

**Scoop Dough:** Quickly scoop the dough into 30 portions using a 1-tablespoon capacity scoop onto the prepared baking sheet. Arrange them about 1½ inches apart. (Work fast to maintain the shiny and crackly tops.)

**Bake:** Bake the cookies for 11-12 minutes until the tops have cracked. If desired, use a circular cookie cutter to reshape them while they're still warm.

**Cool and Sprinkle:** Let the cookies cool on the baking sheet for 5 minutes, then transfer them to a wire rack to finish cooling. Sprinkle with flaky sea salt before serving.