Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a mixing bowl, whisk together the flour, cocoa powder, baking powder, and salt.
In another bowl, beat the granulated sugar, melted butter, eggs, and vanilla extract until smooth.
Gradually add the dry ingredients to the wet ingredients, mixing until a thick dough forms.
Chill the dough in the refrigerator for 30 minutes for easier handling.
Scoop tablespoon-sized portions of dough and roll them into balls.
Roll each dough ball generously in powdered sugar, coating completely.
Place the coated dough balls on the prepared baking sheet, spacing them 2 inches apart.
Bake for 10-12 minutes, or until the tops are cracked and the edges are set.
Let the cookies cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.