Preheat the oven to 350 ºF or 175 ºC. Line a baking sheet with baking paper and put to one side for now.
In a medium mixing bowl or stand mixer bowl, cream together butter, sugar, egg and vanilla until light and fluffy.
Stir in your flour, cocoa powder, baking soda, baking powder and salt. Combine well, then throw in the chocolate chips.
Roll into small balls, approximately 1" diameter (you could also use a cookie scoop) and put the balls of cookie dough on the baking sheet. Don't put them too close together as they'll spread when they're baking.
Bake for 9-11 minutes then take them out of the oven. Move to a wire rack to cool. The cookies will still seem soft but should firm up slightly as they cool.