In a medium mixing bowl, whisk together the flour, cocoa powder, salt, baking soda, baking powder and espresso. Set aside.
In the bowl of a stand mixer, or large mixing bowl, add the butter and sugars. Beat on medium speed until creamed, about 3 minutes.
Add in the egg and mix until combined. Then add in the milk and vanilla. Mix until combined.
Add half the dry ingredients and mix until just incporated. Srape down the sides of the bowl and add in the rest of the dry ingredients. Mix until fully incporated.
Mix in the chocolate chips. Cover the bowl with saran wrap and place in the fridge for at least 2 hours.
Preheat your oven to 350℉. Line or spray a baking pan.
Scoop 1 1/2 tbsp size cookies and make sure they're at least 2 inches apart. Bake for 8-9 minutes or until the edges just barely start to feel firm.
Allow to cool to room temperature and store in an airtight container for up to 4 days.