Preheat oven to 325° F with the rack in the middle.

Combine the chocolate and butter in a bowl and microwave at 50 percent power until melted, stirring occasionally, about 2 to 3 minutes. Let cool slightly before they are mixed with the eggs in step 5.

Combine the flour, cocoa, baking powder, baking soda, and salt in a bowl and whisk together.

In a large mixing bowl, whisk together the brown sugar, eggs, espresso powder, and vanilla.

Whisk the chocolate mixture into egg mixture until combined.

Fold in the flour mixture until no dry streaks remain. Let dough sit at room temperature for about 10 minutes until the dough is workable. If your kitchen is very warm you can rest the dough in the refrigerator. (See Notes)

Roll the dough into 2-tablespoon sized balls (about 40g). Roll in the granulated sugar until well coated. Roll in the powdered sugar until well coated. Then place on a parchment lined baking sheet.

Bake one sheet at a time at 325° F until the cookies are puffed and cracked. The edges will have begun to set, but the insides will still look undone in between the cracks, about 12 minutes. Don’t overbake.

Remove from oven and let cool on baking sheet for about 10 minutes, then transfer to a cooling rack or enjoy warm.

Store in an air-tight container at room temperature for up to 5 days or freeze for up to 3 months.