Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a medium bowl, whisk together the flour, cocoa powder, baking powder, and salt.

In a large bowl, combine the granulated sugar, brown sugar, and vegetable oil.

Add the egg and vanilla extract to the sugar mixture, mixing until well combined.

Gradually add the dry ingredients to the wet ingredients, stirring until a dough forms.

Chill the dough in the refrigerator for about 30 minutes to firm up.

Once chilled, scoop out tablespoons of dough and roll them into balls.

Roll each ball in powdered sugar until fully coated.

Place the dough balls on the prepared baking sheet, spacing them about 2 inches apart.

Bake in the preheated oven for 10-12 minutes, until the edges are set.

Allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.