**1. Make the Dough:**
- In a large bowl, mix granulated sugar, vegetable oil, and cocoa powder until smooth.
- Beat in the eggs one at a time, then add vanilla extract.
- In a separate bowl, whisk together flour, baking powder, and salt. Gradually add the dry ingredients to the wet ingredients, mixing until a thick dough forms.
**2. Chill the Dough:**
- Cover the dough with plastic wrap and refrigerate for at least 2 hours, or overnight, to firm up.
**3. Preheat and Prep:**
- Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper or silicone baking mats.
**4. Shape and Coat:**
- Roll the chilled dough into 1-inch balls, then generously coat each ball in powdered sugar.
**5. Bake:**
- Place the coated dough balls onto the prepared baking sheets, spacing them about 2 inches apart.
- Bake for 10-12 minutes, or until the cookies are set but still soft in the center. The cookies will puff up and crackle as they bake.
**6. Cool and Serve:**
- Allow the cookies to cool on the baking sheets for 2-3 minutes, then transfer them to a wire rack to cool completely.