Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a mixing bowl, whisk together flour, cocoa powder, baking powder, and salt.
In another bowl, blend granulated sugar, brown sugar, and vegetable oil until smooth.
Add eggs and vanilla extract to the sugar mixture, mixing well.
Gradually incorporate the dry ingredients into the wet ingredients until just combined.
Chill the dough in the refrigerator for about 30 minutes.
Using a cookie scoop, form balls of dough and roll them in powdered sugar.
Place the coated dough balls on the prepared baking sheet, spacing them about 2 inches apart.
Bake for 10-12 minutes, or until the edges are set but the centers remain soft.
Let the cookies cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.