In a medium bowl, whisk together the sifted cocoa powder, sugar, eggs, vegetable oil, and vanilla until smooth.

In another bowl combine the flour, baking powder, and salt. Stir to combine.

Gradually add the dry ingredients into the wet until an even brownie-like batter is formed. Cover the dough, and chill for at least 2 hours (At this point, the dough can be refrigerated for up to 5 days or frozen for up to 6 weeks)

Preheat oven to 350°F (180°C) and line 2 cookie sheets with parchment paper.

After chilling, use a 1 tablespoon measure to scoop your cookies. Roll the dough between the palms of your hands to achieve a rounded ball. Scoop roughly 30-35 cookies. Roll each cookie dough ball in powdered sugar. Place dough balls 2 inches apart on prepared baking sheets.

Bake in preheated oven for 10 to 12 minutes. Take care not to over bake. Allow standing on the cookie sheet for 20 minutes before transferring to wire racks to cool completely.