In a large bowl with a hand mixer, or the bowl of a stand mixer, add cocoa powder, oil, and sugar. Mix together. Add the eggs 1 at a time and stir well after each. Add the vanilla, baking powder, flour, and salt.
Cover and allow to chill in the fridge for 1 hour.
Preheat oven to 350° F. Grease a baking sheet. Place the powdered sugar into a small bowl to roll the dough balls in.
Using a medium cookie scoop (2 Tablespoon size), drop a scoop of the cookie dough into the powdered sugar. Roll until it is fully covered. Place dough ball onto the greased cookie sheet. Repeat with remainder of the dough, placing balls about 1 1/2 inches apart.
Bake for about 10 to 12 minutes.