Preheat the oven to 300 degrees F and line 2 baking sheets with parchment paper. To a medium bowl, set over a saucepan of simmering water, add the chocolate and butter; allow to melt and then stir until smooth, about 5 to 7 minutes. Set aside to cool slightly.

In the bowl of a stand-up mixer, using the paddle attachment, add the eggs and sugars. Beat until the powdered sugar is completely incorporated and the color of the mixture turns a light yellow. Add the vanilla and salt. Next, with the mixer on low, add the reserved melted chocolate and mix until completely incorporated. Scrape down the sides of the bowl and then add the flour and baking powder. Scrape down the sides once more and give it one last mix. Lastly, fold in the walnuts. The mixture will resemble more of a batter than a dough. It should be shiny and wet.

Using a #20 ice cream scoop (essential two heaping teaspoons worth of batter or 2 ounces), drop mounds of dough, spacing them about 2 inches a part. If the mound doesn’t seem like it will spread into a perfect circle, don’t be afraid to shape it with your finger. I did this and was glad I did. Transfer the baking sheet to the oven for 5-7 minutes, until the cookies appear crackly and wet in the center and slightly puffed.

Leave the cookies on the baking sheet to cool, about 10 minutes, and then using a very thin spatula, such as a fish spatula, move the cookies to a cooling rack. Repeat with the remaining dough/batter until all the cookies are baked. Sprinkle the cookies with sea salt for garnish. If you’re transporting the, be sure to put a sheet of parchment between stacks since these cookies do like to stick together a bit when you piled them.