1. In a medium mixing bowl, whisk together the granulated sugar and vegetable oil until glossy and well combined.

2. Add the eggs one at a time, whisking well after each addition, until the mixture looks thick, smooth, and slightly pale.

3. Stir in the vanilla extract until evenly incorporated.

4. In a separate bowl, whisk together the all-purpose flour, unsweetened cocoa powder, baking powder, and fine sea salt, breaking up any cocoa lumps.

5. Add the dry ingredients to the wet ingredients and fold gently with a spatula just until no streaks of flour remain; the dough will be thick and sticky.

6. Fold in the mini semisweet chocolate chips until they are evenly distributed throughout the dough.

7. Cover the bowl and refrigerate the dough for at least 1 hour, or until firm enough to scoop and roll into balls.

8. When ready to bake, preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

9. Place the extra 1/4 cup granulated sugar in one shallow bowl and the powdered sugar in another shallow bowl.

10. Scoop the chilled dough into small balls (about 1 to 1 1/2 tablespoons each), then roll them between your hands to smooth.

11. Roll each dough ball first in the granulated sugar, shaking off excess, then generously coat in powdered sugar.

12. Arrange the coated dough balls on the prepared baking sheet, leaving a couple of inches between them for spreading.

13. Bake for 9–11 minutes, or until the cookies have puffed, cracked, and look set around the edges but still soft in the centers.

14. Let the cookies cool on the baking sheet for 3–5 minutes, then transfer to a wire rack to cool completely.