[Obsessive Costuming Dude (Alex)]

If I'm understanding you correctly, the “front” and “back” of the cape are one continuous piece (cut on the fold, if the fabric you're using is wide enough).

There are two pieces that need to be connected; the upper piece is the one with the pleated neckline, and the second piece is a lower extension that is cut to the desired length. The two pieces are joined to create the full cape.

Could you be more specific with your pleating issue, and possibly include a photo? I might be better able to help you that way with those.

– Alex