Either they taste like thin mints or mint milano cookies, you decide!  I think they're even better than thin mints -- definitely more like the Pepperidge Farm milanos!

     COOKIE INGREDIENTS
      2/3 cup butter, softened
     1 cup sugar
     1 teaspoon baking powder
     1/4 teaspoon salt
     1 egg
      1 tablespoon milk 
     1 teaspoon of peppermint extract 
     4 drops of green food coloring
     2 cup flour

     1 cup semi-sweet chocolate chips or chunks
     1/4 cup vegetable shortening
     16 Canadian peppermints, finely ground 
           into dust and small pieces 
           (about 1/2 cup after ground)

Cream butter & sugar.  Mix in other ingredients one a time, stirring thoroughly.  Split dough into 3 parts, wrap in cling wrap and chill for at least 1 hour.  Roll out, cut out and place on an ungreased cookie sheet.  Cook at 375 degrees for 11 minutes.

Remove at the first sign of browning on the edges (or before) - do not overcook.  Cool on wire racks.

Melt shortening in a double boiler than turn down to low heat (a 2 out of 10 on my stovetop) and add chocolate.  Let it slowly melt and stir.

Dip cookies upside-down into chocolate then sprinkle with ground peppermint candies.  Store on refrigerator.  Makes about 60 cookies, depending on how small you cut them out.