Sift flour, coco powder, baking soda, salt well in a bowl. Pre heat oven at 180 Deg C for 10 mins.
In another mixing bowl, place butter at room temperature, both brown and white sugar and beat with electric hand blender to creamy pale mixture.
Add vanilla and mix with spatula.
In goes the dry ingredients we sifted in step1.
Mix with hands to a crumbly dough.
Add chocolate chips, 1 tbsp milk and make dough. I used chocolate from the fridge and cold milk. So my cookie did not spread well. You can add in room temperature or little extra milk for more flat cookies.
Divide into 18 - 20 equal sized balls. Use cookie scoop or a ladle to equally portion the dough.
Place in a baking tray lined with parchment paper. Leave 1 inch space for the cookie to spread.
Bake in middle rack for 10 mins. Bake 2 more minutes if the cookie didn't spread well after 10 mins.
The cookie will be soft once you take out from oven, but as cools down, it hardens.