In a stand mixer or by hand, combine oil, chocolate, and sugar. Stir in eggs one at a time, followed by vanilla. Add dry ingredients a little at a time until dough is well mixed.
Cover dough and chill at least 2 hours.
Preheat oven to 350. Lightly grease cookie sheets, or cover with parchment paper.
Chilled dough will still be soft. Shape tablespoons of dough into balls and roll in powdered sugar.
Bake for 10-12 minutes (they’ll appear undercooked). Remove to cooling racks immediately.
Notes
Cookies freeze well! They can be brought to room temperature or eaten half-frozen (my personal favorite).