Some two-in-one DIY inspiration... I'm thinking you start with a ruffled A-line skirt perhaps a size or two too large. Slice down the middle, hem sides to fit your waist and add snap buttons or a zipper (buttons seem easier to manage). Sew or glue embellished ribbon to the waistband, and leave it long if you want it to tie as well as button. Wear it around your shoulders as a ruffled cape, or at your waistline buttoned up as the original skirt. One of those projects that sounds super easy, but I'll stlll never get around to doing.
For the lazy, you could always just buy it at 80s Purple: Velvet Leaf women's constance cape/skirt.