The ad, "first taste, first love" will break on TV screens in the UK and Ireland from March 20.
The first shot of the ad, with a 1970s feel, opens on a school coach and shows a teenage boy reaching out to a pretty girl in front of him and bringing a shy smile to her face by sharing some of his Cadbury Dairy Milk.
As she eats the chocolate she falls in love for the first time. The following scenes cut from the young couple's first date to their wedding day and a family photography session with their new baby, who later morphs into a teenage boy.
History repeats itself as the scene is brought up to date and it is now the son on the coach following in the footsteps of his parents, as he offers a girl on the bus a little piece of his Cadbury Dairy Milk.
Simon Baldry, managing director of Cadbury Trebor Bassett, said: "Cadbury Dairy Milk is an iconic brand that has been the nation's favourite chocolate taste for most of its 100 years."
The spot was written by copywriter Roger Rex and art director Roger Sealey and directed by Joe Roman. The production company for the ad was Knucklehead, while the media planning and buying was handled by Starcom.
"This ad captures the emotional bond that consumers experience when they first taste the chocolate brand," Baldry said
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