What could be easier?
Let the yarn do all the work A simple rectangle with a neck opening plus a turtleneck for warmth.

Eliminate the curl by adding ribbing along the edges.

Knit the ribbing and collar by hand or machine for a beautiful finish.

One version of the original poncho is knit in Brioche. Machine knitters can substitute English Rib | Half Fisherman Rib or Fisherman Rib
DIY and make it your own!