The Popularity Spell — Toni Gallagher

Magic and a little twist of mayhem will charm fans of Sarah Mlynowski, Lauren Myracle, and Wendy Mass in this fresh, contemporary novel!
 
When a package arrives in the mail for Cleo Nelson, she can't wait to open it. The birthday present is seven months late, but it's from Uncle Arnie and that can only mean one thing: magic! Inside is a voodoo doll complete with instructions for making happy, wonderful things happen to Cleo and her friends -- err, friend. Just one, really. But maybe the doll can change that....
           
Cleo can't wait to try out the magic with her friend, Samantha. They start small by wishing for treats (surprise pizza!), but then their spells start to grow. And when they wish for popularity, they accidentally get the popular girl in school in major trouble with the principal. Can happy spells be twisted into bad magic?