In a large bowl combine the all purpose flour, baking powder and salt. Whisk well and set aside.

In a large mixing bowl, mix the sugar and the oil on low speed until well combined. Add the cocoa powder and mix again until well blended, make sure to scrape the sides of the bowl to incorporate it well. Beat in the eggs one at time, as well as the vanilla extract. Slowly add the dry ingredients, in two batches if necessary, and scrape the bowl again to incorporate everything really well.

Cover the bowl with plastic wrap and refrigerate for at least 4 hours (preferably overnight).

Preheat oven to 350ºF (180ºC) and line a cookie sheet with parchment paper or a silicone baking mat.

Shape the dough into 1 inch (2.5 cm) balls (using a small ice cream scoop works best) and roll them in the powdered sugar. For whiter cookies you can tap off the excess and roll again about 3 times.

Place them on the prepared cookie sheet, about 2 inches (5 cm) apart and bake for about 10-12 minutes or until the tops are crackled. Let them cool in the cookie sheet for about 2 minutes and then transfer to a wire rack to cook completely.