In a mixing bowl, whisk together the flour, cocoa powder, and salt until well combined.

In the bowl of an electric stand mixer, beat together the butter and powdered sugar on low speed until mixed. Then, increase to medium speed and continue mixing until light and fluffy, about 2 minutes.

Scrape down the sides of the bowl and blend in the vanilla extract.

Gradually add the flour mixture and blend on low speed until it forms clumps. Knead the dough a few times by hand if necessary.

Divide the dough into two equal portions and roll each into a log about 5 1/2 inches long. Wrap each log in parchment paper or plastic wrap and chill in the refrigerator for 1 hour.

Preheat your oven to 350°F (175°C) during the last 15 minutes of chilling.

Line two baking sheets with parchment paper.

Remove one log from the refrigerator, and cut it into slices about 1/3 inch thick. Arrange the slices on the prepared baking sheets, spacing them about 1 1/2 inches apart.

Bake the cookies in the preheated oven until set, about 11 to 13 minutes.

Let them cool on the baking pan for 10 minutes before transferring to a wire rack.

For an added touch, dip half of each cooled cookie into melted chocolate and let the excess drip back into the bowl. Transfer to a lined cookie sheet to let the chocolate set.