doubles as the front and back pieces.
you have the option of making the hat reversible by making both the exterior and lining out of fleece.
you can also make the lining out of jersey knit.
with right sides together sew the front of the exterior to the back of the exterior (note that the front and the back of the hat are not symmetrical. use a .5 inch seam allowance sew the side seams together leaving the v open. repeat with the lining.
then turning the hat, sew the v shut. (pinch the v together, right sides of the front together, right sides of the back together, pin, sew together in one continuous 