Roll each into a log about 9 inches long. Place, well spaced, on baking sheet. Flatten slightly with fingers. Bake until lightly browned about 18-24 minutes. Cool 15 minutes then transfer to work surface.
Place cookies back on baking sheet.
Reduce oven heat to 325. Bake again, 15-20 minutes, turning once at midpoint, until cookies are slightly colored and seem dry. To glaze, melt 8 ounces of semi sweet chocolate. Using a flat, small icing knife, spread melted chocolate on one side of each cookie. Cool on rack 2-4 hours until thoroughly firm.