It should be noted that besides an award winning acting career, Ethan Hawke is also a somewhat acclaimed novelist. His three novels include:
The Hottest State: A Novel (Little Brown & Co. 1996)
His first and most critically acclaimed book is a Genration X romance that takes the lovers, William and Sarah, from the Lower East Side to Paris and through a passionate relationship.
Ash Wednesday (Knopf 2002)
The story of Jimmy Heartsock, an Army soldier stationed in Albany who goes AWOL with his pregnant girlfriend and drives from New York to Texas in a Chevy Nova.
Manhattan Story (Fayard 2003)
by Ethan Hawke, Catherine Charmant
Which I can't find any information on... but I am guessing takes place in Manhattan and is a quirky romance between over passionate twentysomethings.
It should also be noted that I have not read any of the aforementioned books.