Make hat: Melt candy following package directions. On waxed paper, pipe an oval disc 1 ½ x 2 ½ in., let set. Cover a corn snack with melted candy and let set. Attach hat peak to brim with melted candy, let set.
Make and decorate witch cookie: Roll out cookie dough and cut out pumpkin shape using Grippy cutter. Trim off stem, bake and cool. Thin green royal icing with small amounts of water until pouring consistency and cover cookie. Let dry. Position pumpkin face stencil on cookie, cover with black royal icing, smooth and remove stencil. Pipe tip 16 orange pull out star hair. Attach hat to cookie with melted candy. Pipe tip 3 violet hatband.
Combine leaf green and lemon yellow for green shown. Combine violet and rose for violet shown. Divide royal icing and tint colors shown.