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

In a large mixing bowl, mix sugar, oil, and vanilla. Add eggs one at a time, beating well.

Stir dry ingredients into wet until just combined. Chill dough at least 2 hours.

Preheat oven to 350°F and line baking sheets with parchment.

Roll tablespoon-sized dough balls and coat in powdered sugar.

Place 2 inches apart on baking sheet.

Bake 10–12 minutes, until tops are crackled.

Cool on sheet a few minutes, then transfer to wire rack.