It's true, authors are just like rock stars to us here in the NU library. And many of them have great web pages and love hearing from their readers. Many of the authors that I've met at conferences seem actually eager to hear from kids and will write back to you if you contact them.
Click around to visit some of Ms. Sonnenberg's favorite authors, or just go to this article to get started: https://bookriot.com/2014/07/22/15-author-pages-like-facebook/
Ellen Hopkins (Crank, Burned, Glass, Impulse, Identical, Tricks and several others)
Chris Crutcher (too many books to list, but an amazing guy and real champion for teenagers and intellectual freedom)