Combine cocoa, sugar and oil in a mixer and combine until well mixed. Add eggs and vanilla and mix again until well combined.
In a separate bowl combine flour, baking powder and salt and stir with a whisk until everything is combined. Slowly add to the chocolate mixture and mix until everything is combined.
Place dough covered in the fridge and let chill for at least 3 hours.
Preheat oven to 350 and then scoop out tablespoon sized balls and roll between your palms. Roll in powdered sugar and give each dough ball a good coating. Place on a cookie sheet. Bake for about 10 minutes and let cool slightly before moving to a cooling rack.