This one was about as easy and fast a hat as you can make. It is made on two needles instead of circular if that matters to you. It is just garter stitch with increases and decreases. And if you want to take a break from casting on and binding off, you start with three stitches and end with three stitches. Give it a try.
https://www.ravelry.com/patterns/library/diagonale-3
By the way, it is a free pattern. Be sure to thank the Woolly Wormhead.
https://www.ravelry.com/patterns/library/diagonale-3