Chloe Grace Moretz declined a doorstep offering of cookies from a young male admirer ... and reported him to authorities instead.
Law enforcement sources tell TMZ ... the "Neighbors 2" star had an uninvited guest roll up to her home on a skateboard with a container full of treats. We're told Chloe was inside but didn't answer. The guy asked a neighbor if this was Chloe's home, and the neighbor started grilling the guy.
Cops say Moretz called the cops and reported the guy, who looked about 18. The cops never got to speak with the guy because he made a hasty retreat.