I wound up the yarn, and casted on for the hat anyway.
The name of the hat is Sand Bank by Justyna Lorkowska. It's a slouchy cabled hat, and I intend to add a huge Pom-Pom to it.
I used a stretchy German Twisted Cast-On, but I'm wondering if I should go up another needle size. The hair on my head is quite curly and fluffy, and I need to make sure the hat will be able to fit around it properly. Hmmmmmmmmm
Also, to get the cable needle needed for the hat, I had to remove one of the needles from my sweater. The good thing is, I was finally able to fix the twisted back. Now it hangs just right.