Preheat oven to 350*F. Prepare baking trays with parchment paper for scooping cookies.
In a small sauce pan melt butter. Add all of the chocolate and stir to melt of low heat. When most of the chocolate is melted, take off the heat. The residual heat will continue to melt the remaining chocolate.
Let cool slightly while you get the eggs ready.
In a medium bowl beat eggs, sugar and vanilla extract with a handheld mixer or by hand with a whisk until pale and foamy. This usually takes 3-5 minutes.
Add in espresso powder and continue to whip.
While whisking very fast, slowly pour in the melted butter and chocolate mixture until it is all incorporated. You want to make sure to continue to whip the egg mixture vigorously while adding to keep the mixture light and frothy.
With a sieve, sift flour, baking soda, salt, and cocoa powders on top of the chocolate mixture.
With a spatula carefully fold in the dry ingredients making sure not to be too rough. Your dough will resemble thick and shiny brownie batter.
Using a 1 ounce scoop, scoop 6 cookies per baking sheet. You will want to scoop as many as you can. If you have 4 baking sheets, scoop all the batter at one time onto the trays. This will help preserve the crackle crust on the cookies.
Bake cookies for 10-12 minutes, making sure not to overbake. They will look slightly underdone and soft in the middle.
Cool on pan for at least 5 minutes before carefully moving to a wire rack to finish cooling. You can sprinkle sea salt on top while they are still warm.