In a mixing bowl, combine sugar, cocoa powder, oil, vanilla extract and eggs. Whisk until the mixture is smooth.
In a separate bowl, combine flour together, baking powder and salt. Add the flour mixture to the cocoa mixture and stir to combine. Cover the dough with plastic wrap and refrigerate for at least 3 hours and up to overnight.
Preheat the oven to 350F. Scoop dough with a mini ice cream scoop for even portioning into 20 cookies then roll cookie dough into even-sized balls (it's easier to roll with wet hands) and generously roll each into powdered sugar.
Place cookies on a baking sheet, being sure to leave space between each of the cookies. Bake for 10-12 minutes, depending on the size of the cookies.
Cookies will come out soft but will harden as they cool down. Allow cookies to slightly cool. Then, move them to a wire rack to fully cool down. ENJOY