Preheat your oven to 350°F and line two baking sheets with parchment paper.

In a medium bowl, whisk together the flour, cocoa powder, baking soda, and salt. Set aside.

In a large bowl, cream the softened butter and granulated sugar together until light and fluffy, about 3-4 minutes.

Add the egg and vanilla extract, mixing until well combined.

Gradually add the dry ingredients to the wet mixture, mixing until just combined.

Chill the dough in the refrigerator for at least 30 minutes for easier handling.

Once chilled, scoop tablespoon-sized portions of dough and roll them into balls.

Roll each ball in powdered sugar until fully coated.

Place the cookies on the prepared baking sheets, spacing them about 2 inches apart.

Bake for 10-12 minutes, or until the edges are set but the centers are still soft.

Allow the cookies to cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.