Cream the butter and sugar in a mixer, then add salt, vanilla, and cocoa powder. Add the flour, and continue to mix until it just comes together. Turn out the dough, roll it into a ball, and then flatten to a disk, place in a plastic bag, and put it in the freezer for 20 minutes. Then roll it out very, very thin. Cut out cookies and place on a baking sheet and bake for 10 minutes at 350.

Melt the chocolate, stirring occasionally. Stir in the peppermint. Coat the cookies, then let cool.