I made the Rock Cowl to go with the Rock Cap. The pattern is worked in the round and yields a cowl that is 24 cm in diameter (9.5”) and 25 cm tall (10”) when flat. It has stretchiness. It is sized for a teen/adult but can be adjusted to your needs. This pattern yields a cowl that fits snug and stacked on the neck. If you would like a wider cowl, you only need to increase the cast on stitches to the width you desire. Just make sure there are an even number of stitches. I used less than 2 skeins for this.

Rock Cap pattern:
https://www.ravelry.com/patterns/library/rock-cap