Sift together the flour, salt and cocoa powder.
In a separate bowl, beat butter and sugar together until it creates a creamy and somewhat fluffy consistency.
Then beat in the egg and vanilla until well blended.
Gradually add in sifted mixture.
Turn dough onto a piece of plastic wrap and seal completely. Place in the refrigerator until firm (about 1 1/2 to 2 hours).
Preheat oven to 375 and line cookie sheets with parchment paper or use silpat.
Lightly flour your hands, and start pulling your dough and rolling into 9 inch long ropes. Bring the ends together and pull to center of cookie to make a pretzel.
Dust each cookie with sugar. If you wish, you can brush egg white on each cookie to create a glazed effect.
Bake for approximately 10 - 11 minutes.
Allow to cool on cookie tray before transferring to cooling rack.