Combine ice cream, Creme de Menthe, milk and salt in a blender. Blend on medium speed to combine. If needed, add a bit more milk to achieve desired consistency.
Use a knife to coat the rim of each mason jar with a thick layer of chocolate syrup. Sprinkle sugar pearls along the rim of each jar. Divide milkshake among the jars.
Top with whipped cream and caramel sauce. Stick one chocolate Pirouette and mint cookie into each shake. Place a cherry on top and ta-da!