Melt chocolate in a double boiler or microwave in 30 second bursts and add to piping bag. Take reeses cups out of wrappers.

Pipe a large dot of chocolate onto cookie to secure peanut butter cup onto cookie. Place base of peanut butter cup down to "glue" to cookie.

Pipe chocolate onto backs of candy eyes, and secure onto peanut butter cups. If eyes slide down, let chocolate cool slightly.

Pipe four legs per side of peanut butter up to complete spider.

Let set for at least 30 minutes.