Preheat oven to 350 degrees. Line a cookie sheet with parchment paper and set aside.

Combine cocoa powder, sugar and oil in a mixing bowl and beat together. Mix in egg plus 1 egg yolk and vanilla.

Add flour, baking powder and salt and mix until combined. Add chocolate chips. Form dough into a ball in your bowl and place bowl in freezer for 10-15 minutes to chill. It's the perfect amount of time to clean up :)

Sprinkle powdered sugar over dough ball and roll around to coat.

Place on cookie sheet and gently flatten to 7-inches in diameter. (Tip: Sometimes the warmth of your hand pressing down the dough melts the powdered sugar on top! Feel free to sprinkle on a little extra before baking.) Bake for about 11-13 minutes until edges look set and center looks puffed but soft. you should see some small crinkles and more will appear while cooling! Carefully transfer to a cooling rack. We actually prefer this cookie cooled rather than warm so do your best to wait!