Miley Cyrus is a pothead, according to Miley Cyrus. Or is saying "You know you're a stoner when your friends make you a Bob Marley cake..." not an admission of guilt but just a big misunderstanding?

During her 19th birthday bash in LA last week, the former Disney star -- caught on video smoking salvia on her last birthday -- told her guests, "You know you're a stoner when your friends make you a Bob Marley cake. You know you smoke way too much (effing) weed!"

The Daily has the scoop...and the video!

Kelly Osbourne, who threw the party for Miley, says her friend was just joking, tweeting: "Let me make something very clear after Miley's salvia incident -- we started calling her Bob Miley as a joke! The cake was also a joke! It makes me sick that Miley's so-called 'friends' would sell her out and lead people to believe she is someone that she is not."

Whatever.