Bewitched

Bewitched is book two in the Betwixt & Between series by NY Times and USA Today bestselling author Darynda Jones

Forty-something Defiance Dayne only recently discovered she comes from a long line of powerful witches. Added to that shocker was the teensy, infinitesimal fact that she is what's called a charmling. One of three on the entire planet. And there are other witches who will stop at nothing to steal her immense power, which would basically involve her unfortunate and untimely death. 

No one told her life after forty would mean having to learn new life skills-such as how to survive a witch hunter dead set on killing her-or that the sexiest man alive would be living in her basement. 

Whoever said life begins at forty was clearly a master of the underappreciated and oft maligned understatement.