Preheat oven to 350°F/176°C
In one bowl add flour, cocoa powder, espresso, baking soda, and salt with a whisk fully mix all of the dry ingredients together thouroghly. NOTE: this does not include any of the sugars.
Melt the butter not till it is liquid, but till it is creamy.
In a large mixing bowl add the butter, brown sugar, and white sugar and fully mix until all the sugars are melted and fully integrated.
Add one of the eggs to the butter and sugar, and fully mix, then add the second egg and mix well. NOTE: Do not add both eggs at once as they don't always mix completely when you do that.
Add the flour mixture into the butter mixture a little bit at a time until it is all added in. Continue to stir until all of the flour/espresso/cocoa is fully integrated into the mix.
Add the chocolate chips into the cookie dough making sure to evenly distribute them.
Cover the cookie sheets with parchment paper.
Spoon out the cookie dough in small 1 tablespoon clumps, with about 2" separating the clumps on the parchment paper covered baking sheets.
Bake the cookies for 10 - 12 minutes in the oven.
When you take the cookies out of the oven let them rest on the baking sheets for 2 - 3 minutes before you transfer them to a cooling rack because they are very gooey when you take them out of the oven.
Let the cookies rest on the cooling rack for about 15 - 20 minutes before you transfer them into an airtight container for storage. They should be able to store them for at least a week, assuming you don't eat them all faster than that.