Using the standing mixer, combine the egg whites, cream of tarter, vanilla and powder sugar and mix until combined and stiff peaks form
Scoop 1 C of icing into another bowl and mix in a few drops of black gel coloring. Add in a few more drops of black to get the shade you want.
Scoop some white icing and black icing into the piping bags and set aside
Add in a few tablespoons of water into the remaining white icing and mix until combined
Pour the white icing into the squeeze bottle
Using the white piping bag, pipe a outline around the cookies
Fill in with the thinner white icing
Let cookies dry overnight
Using the black piping bag, pipe the detail of Jack Skellington's eyes onto the cookie and fill in
Pipe a line for a smile onto the bottom part of the cookie
Pipe small lines for stitching onto the line for the smile
Let cookies dry for an hour before enjoying.