Combine cookie mix, oil, and eggs and mix according to package instructions.
Chill 1 hour.
Roll dough into 1 inch balls; dip balls into granulated sugar and place in well-greased mini muffin tins to bake.
Bake at 350 degrees 13 minutes or until set.
Remove from oven and cool 15 minutes in pan.
Twist each cup gently to remove it from the pan; cool completely on wire rack.
Prepare buttercream frosting by combining butter, powdered sugar, cocoa powder, milk, and peppermint extract in a medium mixing bowl and beating at high speed until smooth and light.
Fill a plastic ziploc bag with frosting; close and snip one corner of the bag to pipe frosting onto the top of each cookie.
Finish with marshmallow bits, Andes baking bits, and decorative straw segments.