Ex-Soap Opera Star Scott Evans -- Charged with Trying to Buy Cocaine from Undercover Cop

Former soap actor Scott Evans -- younger brother of Chris Evans -- has been charged with trying to buy cocaine off an undercover police officer ... a felony ... TMZ has learned.

We broke the story ... Evans -- who played Officer Oliver Fish on "One Life to Live" -- was arrested last week following the alleged drug deal.

A rep for the L.A. County District Attorney tells TMZ, Evans was charged with one count of attempted possession of a controlled substance. He's due in court today for his arraignment.