The expensive option: http://www.walinandwolff.com/cashmere-slouchy-hat-in-grey.html
Cheaper options:
http://www.shophcb.com/collections/hats-ear-warmers/products/slouchy-knit-beanie-gray-taupe-or-black
http://www.amazon.com/dp/B00VHCAZ4Q
http://www.amazon.com/dp/B00BHU14FW
http://www.amazon.com/dp/B00NNU2MD2
Bonus stripes:
http://www.amazon.com/dp/B008737PXC