Bernadette from Daisies and Dresses shares a tutorial at The Sewing Rabbit showing how you can add length and fullness to a cap sleeve pattern. It remains a smooth sleeve cap, with the fullness added to the bottom only. You can make it any length from elbow to 3/4 to full length. Go to The Sewing Rabbit to get her tutorial.
[photo from Daisies and Dresses on The Sewing Rabbit]