A Barbie inspired hat! I have it available for free at my website

Size:
My hat resulted in about 22” in circumference and have 20” size available. Of course if you use a yarn of a lighter weight or smaller needles the hat will result in a smaller size

Gauge:
I think my gauge was 16 sts by 21 rows in stockinette stitch for a 4-inch (10 cm) swatch with 4.5 mm needles, and the yarn label said 18 sts by 24 rows with 5.5 mm needles.

Materials:
You will be needing 3 colors for this one, I used medium weight yarn (4) for the hat:

Color A for the body
Color B for the duplicate stitch for the border of the head
Color C for the duplicate stitch for the head
4.0 mm circular knitting needles
4.5 mm circular knitting needles
4.5 mm double-pointed knitting needles
needle to weave ends
stitch marker