Gather all ingredients.

Cover the flat side of 4 cookies with melted dark chocolate; tap the cookies lightly to smooth out the chocolate.

While still wet, use a piping bag or spoon to make a ghost shape with the white chocolate; tap lightly once more to smooth as needed. More white designs can be added to the dark chocolate background if desired.

Use melted dark chocolate to make the eyes and screaming mouth; tap or shake once more to even and smooth out.

Let chocolate cool until hard and dry to the touch, at least 1 hour.

Scoop ice cream on the flat side of 4 remaining cookies, and cover with the decorated tops. Carefully press to flatten, and transfer to a freezer to freeze thoroughly before serving.