How do I start talking to this girl?

She works at a bread store I go to all the time and she's waited on me like 10 times and she is absolutely gorgeous, but I'm pretty shy and I don't know how to let her know I am interested. She recognizes me now and smiles at me when I walk in but I don't know what to do next. Also, it's like 15 miles from my house and I don't have a car so I ride my bike there and I'm always sweaty haha so that makes it kinda tough too.