Place almond bark or white chocolate in a microwavable bowl or mug.
Lay your cookies out on a piece of wax or parchment paper, or prop them up using a cooling rack by putting each cookie in between the bars of the cooling rack.
Microwave for 30 seconds at a time, stirring in between, until it has melted smoothly.
Put the melted bark in a sandwich baggie and snip a little bit off of one corner to make a hole.
Squeeze melted bark over the top arc of the cookie then gently tape the bottom of the cookie against a flat surface to make the melted candy begin to ooze down the cookie. Shift it from side-to-side to create uneven edges on the bottom of the ghost.
Let the almond bark dry then pipe on eyes by melting chopped chocolate, adding it to a sandwich baggie, and cutting a hole in one corner.
Pipe three circles on each ghost cookie, 2 eyes and a mouth.
Let dry completely then store in an airtight container until ready to serve.