Changes:

Cast on 72 stitches on needle size 3,5 mm. Knit 6 rows. Change to needle size 4 mm. Knit until the hat is 12 cm from edge.

I-cord is knitted whit 5 stitches.

Notes:

The yarn was enough for both hat and baby mittens. Here is pattern for baby mittens (http://www.ravelry.com/patterns/library/baby-mitts-2) and my baby mittens project (http://www.ravelry.com/projects/frokengron/baby-mitts).