Preheat the oven to 180 Deg C.
Line 2 baking sheets with parchment paper.
In a large bowl, sift the cocoa powder, all purpose flour, baking powder and salt.
In another bowl, beat the butter and sugar with the help of electric mixer or your hand mixer (2-3 mins).
Add the egg and vanilla extract and beat until incorporated.
Add the dry ingredients to the wet and mix until just incorporated. Do not overmix. Fold in the chocolate chips.
Using an ice cream scoop or two spoons, place about 1 1/2 tablespoons of batter on the prepared baking sheet.
Do keep about 2 inches space in between as the cookies will expand during baking.
Bake for approximately 8-10 minutes until the cookies are still soft in the center but firm on the edges.
Remove from oven and let it cool on the baking sheet for about 5-10 minutes.
After 5-10 minutes remove and let it cool an a wire rack.
Cool it completely before storing in an air tight container.