Adjust oven rack to middle position and preheat oven to 350F degrees. Line 2 baking sheets with parchment paper or silicone mats.
In a medium bowl, whisk together the flour, cocoa powder, baking powder, and salt.
In a large bowl, whisk together the brown sugar, oil, eggs, and vanilla extract until mixed and smooth.
Using a spatula, gently fold in the dry ingredients into the wet ingredients until no flour streaks remain. Fold in the chocolate chips until just incorporated. Cover and refrigerate the dough for at least 1 hour.
In a shallow dish, spread the confectioners' sugar. Using a small cookie scoop, drop 2-tablespoons of rounded dough into sugar and roll to coat. Space cookie dough balls evenly, about 2 inches apart, on prepared baking sheets.
Bake cookies 1 sheet at a time until they puff up and 'crack' - about 10-12 minutes. The centers should be soft and will even look a bit under-baked. Rotate baking sheet half-way through baking time to bake evenly.
Let the cookies cool on the baking sheet set on a wire cooling rack for about 5 minutes before transferring to a wire rack to cool completely. Enjoy!