Tantalize (Tantalize, #1) by Cynthia Leitich Smith. Found in spine out fiction under SMI. Quincie Morris has never felt more alone. Her parents are dead, and her hybrid-werewolf first love is threatening to embark on a rite of passage that will separate them forever. Then, as she and her uncle are about to unveil their hot vampire-themed restaurant, a brutal murder leaves them scrambling for a chef.
If you like puzzles and history, and are entertained by conspiracy theories, or you just like it when patterns from history emerge before your eyes... this is a really good book. Adult reading level, high school+ appropriate content. It's sequel, The Fire, is just as good.