It’s a knitted torus! Here’s the pattern:

The headband is a tube of mostly stockinette stitch with a cable panel running down the center. It is knit in-the-round until it has achieved the right length to go around your head. The result is a super warm, double thick headband. The ends can be sewn, grafted, or bound off together. This is a really great stash buster as it only needs one skein of worsted. It’s super-fast to make, so it’s great for a quick gift. I have made this pattern 3 times, the first using 1 skein of Madeline Tosh Vintage, another one with 1 skein of Brooklyn Tweed Shelter, and the last with 1 skein of Cascade 220 Superwash. They all turned out great.

Before you start knitting, consider how you want to finish. If you want to graft the ends of the tube together, then do a provisional cast on. If you want to sew the ends of the tube together, use a knitted or long tail CO.

Materials

Size 6 circular needle or DPNs
140 Yards worsted weight yarn (pictured is Madeline Tosh Vintage in Mineral)
cable needle
waste yarn for provisional cast on (if using)

Gauge: approximately 4.5 stitches per inch
Finished dimensions: a tube approximately 5 inches across (when flattened) and 9-10 inches long, also flattened (long enough to fit snugly around your head).

Instructions
Using the right CO to match your BO, CO 48 stitches. Prepare the stitches on your needles to knit in the round.

PATTERN REPEAT:
Round 1 K4, P4, K8, P4, K4, K24
Repeat round 1 nine more times for a total of 10 rounds. Round 11 (cable round) K4, P4, slip 4 stiches to cable needle and hold to front of work, K next 4 stitches from left needle, K the stitches on the cable needle, P4, K4, K24.
Repeat round 1 ten more times.
You have completed a pattern repeat of 21 rounds.

Knit the pattern repeat 5 more times for a total of 6 times (6 cable crosses).
When you have completed the 6 pattern repeats, you should have a tube long enough to wrap around your head for a snug fit.
To finish, either graft the ends of the tube together OR bind off and sew them together.

Note,you are creating a donut shape.
I find that it helps to tack the front of the headband to the back at a couple of places along the seam to prevent the headband from rolling.

Block.