Preheat an oven to 350 degrees F and place Silipat or parchment paper over your baking sheets. Place the confectioners' sugar into a bowl and set aside.
In another bowl, stir together the flour, cocoa, baking powder and salt. Set aside.
In a large bowl, using an electric mixer, beat the butter and sugar on medium speed until creamy, scraping down the sides of the bowl until blended. Add egg, one by one, and vanilla. Beat until all ingredients are blended.
Using a tablespoon, scoop up a rounded spoonful of dough and roll into a ball using your hands. Roll the ball in the confectioners' sugar until mostly covered.
Place the balls on a prepared baking sheet and repeat, spacing the balls about 2 inches apart.
Bake cookies until they're cracked and puffed, 10 to 12 minutes. Remove the baking sheet from the oven and set it on a wire rack for 15 minutes. Repeat with all cookies, serve when completely cooled.
Recipe by In Good Taste at https://ingoodtaste.kitchen/chocolate-crinkle-cookies/