I've googled and seem a list of about 24 people in the 'Credits' for the advert, but it does not include the names of the actor and actress. I'm sure I've seen the actor in something quite big, perhaps Line of Duty.
Somebody should have told Cadbury's years ago that "There's a glass and a half in everyone" is wrong. This means that there's a glass and a half in every person (on Earth?). It should be "There's a glass and a half in every one"