Preheat the oven to 350 degrees F (180 degrees C) and line two baking sheets with parchment paper.

In a heat proof bowl add the chocolate and butter, and place over a small saucepan with simmering water. Stir the butter and chocolate every minute or so until it is completely melted and smooth. Remove from heat and set aside.

In a small bowl, stir together the cocoa powder and hot water. Set aside.

In the bowl of a stand mixer fitted with the whisk attachment, beat the brown sugar, granulated sugar, and eggs on high speed for 2-3 minutes until light and pale in color.

Using a rubber spatula, fold in the chocolate-butter mixture and bloomed cocoa powder mixture until fully combined.

Then, add in the flour, espresso powder, baking powder, and salt, and mix until just combined.

Allow the cookie dough to rest at room temperature for about 10 minutes to thicken up.

Using a 3 tablespoon cookie scoop, scoop the dough onto the prepared baking sheets about two inches apart.

Bake the cookies for about 8-10 minutes until they are crackly, shiny, and appear set. Allow to cool completely on baking sheet.

Sprinkle with flaky sea salt and enjoy!