Preheat oven to 350 degrees Fahrenheit and line a large baking sheet with parchment paper or a non-stick baking mat.
Next, in a medium bowl, whisk together the all-purpose flour, cocoa powder, baking soda, baking powder, espresso powder, pinch of cinnamon, and sea salt and set aside.
Now, in the bowl of your electric stand-mixer (w/ a paddle attachment), beat together the unsalted butter until creamy and add both sugars, beating on medium speed until creamy and fluffy, about 2-3 minutes. Beat in the eggs and vanilla. NOTE: Scrape down the sides if you need to.
Scoop the batter out into 1.5 Tbsps amounts and onto the baking sheet, keeping them roughly 1-inch apart. NOTE: I placed 6-8 cookies on each baking sheet to leave enough space in between each one.
Bake for 10-12 minutes until golden around the edges. At the HALFWAY MARK, about 5 minutes in, remove the baking sheet from the oven and carefully bang it onto a countertop a few times (2 or 3 times) before placing cookies back into the oven. This creates a slight "crinkled look" and flattens cookies a bit if too puffy. NOTE: The cookies will look really soft in the middles when you remove them from the oven, however, they will harden once cooled.
Repeat same steps with each round of cookies until entire batter has been used.
Enjoy these cookies with your favorite glass of milk, tea, or coffee.
Bon Appetit!