Step 1

Preheat the oven to 180℃/ 356℉ and line a large baking sheet with parchment paper or a silicone baking mat.

Step 2

Melt the unsalted butter and chocolate in a heat-proof bowl over simmering water and then set it aside.

Step 3

Using an electric hand mixer or stand mixer beat together the egg, granulated sugar, and brown sugar for 5-6 minutes.

Step 4

Pour the melted butter and chocolate mixture into the egg mixture and mix for another minute.

Step 5

Sift in flour, salt, baking powder, and cocoa powder into the bowl and then use a rubber spatula to fold the mixture together.

Step 6

Divide the dough into 6 equal balls using either an ice cream scoop or spoon. Do not soften the surface. You want to try to keep it as rough as possible for a a better crackle surface to form.

Step 7

Place the cookie dough balls onto the prepared baking sheet, leaving enough space in between them to spread. Then sprinkle each cookie with sea salt.

Step 8

Transfer the cookies to the preheated oven and bake them for 12 minutes. They might look under baked but they will set as they cool.

Step 9

When done, remove them from the oven and then use a large cookie cutter or any round kitchen object slightly larger than the cookies, and gently move it around each cookie in a circular motion. This forms perfect rounds and gives the cookies a crackly top.

Step 10

Allow the cookies to cool for a few minutes on the pan and then move them to a cooling rack.