Sift together the flour, cocoa powder, baking powder, and salt into a bowl. Whisk for 30 seconds to combine.

In a separate large bowl, whisk the sugar, oil, eggs, and vanilla for about 1 minute until thick and glossy.

Stir the dry ingredients into the wet mixture just until no dry streaks remain. Cover and chill the dough for at least 2 hours or overnight.

Preheat the oven to 350°F (175°C) and line two baking sheets with parchment. Scoop 1 1/2-tablespoon portions of dough, roll into balls, and coat heavily in powdered sugar twice. Place on the sheets 2 inches apart.

Bake for 10 to 12 minutes, until puffed and cracked on top with set edges and soft centers. Let rest on the pan for 5 minutes.

Transfer to a wire rack to cool completely, then plate and serve.