In a bowl, combine the olive oil, brown sugar, and white sugar. Whisk well for 1-2 minutes. Add the egg and vanilla extract, then whisk for another 1-2 minutes.
In a separate bowl, combine the flour, cocoa powder, baking soda, and salt.
Gradually fold the dry ingredients into the wet mixture. Mix well, then add the dark and white chocolate pieces.
Shape the dough into 10-12 balls, depending on the desired size. Place them on a baking sheet lined with parchment paper.
Bake for 12-14 minutes. Once out of the oven, sprinkle the cookies with a pinch of salt.
