Preheat an oven to 350°F. Line 2 baking sheets with parchment paper.
Put the confectioners' sugar into a bowl and set aside.
In another bowl, whisk together the flour, cocoa, baking powder and salt. Set aside.
In a large bowl, using a mixer, beat the butter and sugar on medium speed until creamy, about 3 minutes.
Add 1 egg and beat on medium speed until blended and repeat with other eggs, add in vanilla and beat until blended.
Add in the flour mixture gradually and beat on low speed just until combined.
No need to roll your balls out. By using a 1 1/2 tablespoon scoop, scoop dough balls out onto a baking sheet with parchment paper and place in fridge for 10-15 minutes to let them harden up. This will make it easy, so you can roll them in powdered sugar effortlessly without getting your hands all sticky. Unless you want to? I hate getting my hands all sticky...so this is also a time-saver!
Now roll the balls in the confectioners' sugar until generously covered and place on lined baking sheets about 2 inches apart.
Bake the cookies until they are crackled and puffed, 10 to 12 minutes, more if still fudgy on top.
Remove the baking sheet from the oven and set it on a wire rack for 15 minutes.
Using a metal spatula, move the cookies onto the rack and let cool completely.
Repeat with the rest of the cookies. Makes about 24 cookies.