I would even say this could be manageable without a pattern. It looks like its only a retangular piece of a drapeable lightweight fabric gathered with a single piece of elatic the waist.
I think if you cut the fabric this way it could work. Before you sew the shoulder seams, you would have to lay two of the top pieces rightsides facing each other and then sew the yoke an turn it inside out. Sorry if this makes no sense at all sewing was never a topic in my english lesson....