Coffeehouse Angel by Suzanne Selfors

Katrina works in her grandmother's coffee shop in a small town in Washington State, which isn't exactly the coolest job, given that it's an old-world Scandinavian coffee shop rather than the ultra hip Java Hut next door. One morning, when she gives a free cup of coffee and muffin to a homeless guy sleeping out behind the shop, this random act of kindness turns her life upside down. She soon learns that the homeless guy is actually a teenage guardian angel intent on returning the favor. Fame and fortune seem like the obvious requests, but after two botched wishes, Malcolm knows Katrina is hiding something from him. But how can she tell him the truth, when her heart's desire has become Malcolm himself?