This hat is made from a mitten chart I found in Magnificent Mittens by Anna Zilboorg. You can make a hat out of any mitten pattern.

For an adult’s hat, you simply double the number of stitches and pattern repeats and knit the same length as you would for a mitten. Making a child’s hat from an adult mitten pattern is a little more complex. In this
hat, I worked 3 repeats of the main pattern for the circumference and I worked for the full length. The hat will not pull down snugly on the top of the child’s head. Instead it will fold over on the top.