Finished size: 8-1/2” long x 9-3/4” across.

My ribbing:
Ch11, sc in 2nd ch from hook and across (10sc).
R2: ch1, sc BLO in ea st for 72 total rows (10 sc).
Sl st ends together.

Body:
Follow pattern through R12 (I had 72 hdc for those rounds and 24 Granny clusters for those rounds.
I started to make decrease rounds from here on out so I could cinch the top easier with fewer stitches as follows:

R13: (Hdc 5, hdc2tog) around, 62 sts
R14: (Hdc 4, hdc2tog) around, 52 sts
R15: (Hdc 4, hdc2tog) around, 43 sts
R16: 15 granny clusters
R17: Rep R5 making Granny stitches with 2 dc instead of 3
R18: 1 dc in each space around (15 dc)
Then close the hat as per instructions.