1. Whisk the flour, cocoa powder, baking powder, and salt together in a medium bowl until well combined and free of lumps.

2. In a large mixing bowl, whisk the granulated sugar, brown sugar, and oil together until sandy and slightly glossy.

3. Add the eggs one at a time, whisking well after each addition, then whisk in the vanilla extract until the mixture is smooth and thick.

4. Add the dry ingredients to the wet ingredients in two additions, stirring gently with a spatula just until no streaks of flour remain.

5. Fold in the semisweet chocolate chips or chunks until they are evenly distributed through the dough.

6. Cover the bowl and refrigerate the dough for at least 2 hours, or until firm enough to scoop and roll into balls.

7. When ready to bake, preheat the oven to 350°F (175°C) and line two baking sheets with parchment paper.

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

9. Scoop the chilled dough into about 1 tablespoon portions and roll each portion between your hands to form a smooth ball.

10. Roll each dough ball first in the granulated sugar, coating it completely, then roll generously in the powdered sugar.

11. Arrange the coated dough balls on the prepared baking sheets, spacing them about 2 inches apart to allow for spreading.

12. Bake for 10–12 minutes, or until the cookies have puffed, cracked, and the centers no longer look shiny but still feel soft.

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

14. Once cooled, serve immediately or store the cookies in an airtight container at room temperature for up to 4–5 days.