In a large bowl, beat the butter until it is nice and creamy. Then add the granulated and brown sugar and beat until everything is incorporated and fluffy. Beat in the egg and vanilla, then set this aside.

In a separate medium bowl, whisk together the flour, cocoa powder, baking soda and salt.

Using the mixer, add the dry ingredients to the wet in batches until it is all added. Then beat in the chocolate chips.

The dough will be thick and sticky. Cover it tightly and chill in the fridge for at least 3 hours and up to 3 days. Chilling the dough develops the flavors, prevents the cookies from spreading too much and makes the dough easier to work with.

Once ready to bake the cookies, remove the dough from the oven. Let them rest at room temperature for 20 or so minutes. Preheat the oven to 350°F. Line a couple baking trays with parchment paper and set aside.

Place the confectioners sugar either in a shallow bowl or in a large Ziploc bag. Scoop about 1.5 tbsp. of and roll into balls. Roll the balls generously into the confectioners sugar or place into the bag with the confectioners sugar and shake to coat.

Place the coated balls of dough onto the prepared baking trays about an inch apart. Bake for 8-9 minutes, rotating the pan halfway through bake time. Cookies will look very soft in the center still. Let them cool on the baking trays for 5 minutes, then move them to a wire rack to cool completely.

Store cookies covered at room temperature for up to 1 week.

You can freeze dough balls before rolling them in the confectioners sugar. Freeze for up to 3 months. When ready to bake, no need to thaw, just proceed to step 6 and bake for 10 or so minutes.