Heat oven to 350°F. Make cookie template by cutting a tombstone shape, 3-1/2 by 2-1/2 inches, out of a piece of paper.
Roll out half of sugar-cookie dough, following rolled-cookies directions on package (you'll need to add 1/4 cup flour). Roll dough into 8-inch circle (1/4 inch thick). Using tombstone template, cut out four cookies. Reroll scraps and cut two more cookies. Place six skewers on large cookie sheet. Place cookies over ends of skewers, pressing dough lightly to secure. Bake 10 minutes, or until golden. Cool 5 minutes; transfer to wire rack to cool completely.
Roll remaining dough and 1/4 cup flour, as in step 2. Cut out a 4-inch crescent-moon cookie, place on skewer on large cookie sheet, and press to secure. Reroll scraps; cut and shape two more tombstones. Attach to skewers and bake.
In bowl, combine confectioners' sugar and milk, stirring until smooth. Place 1/4 cup icing in small bowl, and add yellow food coloring. Tint remaining icing gray with the black paste. Frost moon with yellow icing. Frost tombstones with gray icing. Let dry at least 15 minutes.
Using black decorating icing, inscribe each tombstone. Using icing, attach candy bats to tombstones. Outline the moon with black decorating icing, and dab with icing to attach candy bats.