KATIE & JOSHUA DO-OVER

They're back up Dawson's Creek in canoe for two

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Holmes and Jackson have happily reunited on the NYC set of their new film

HOPELESS romantic Joshua Jackson is determined to permanently win back former flame Katie Holmes as the onetime Dawson's Creek couple shoots a new movie together, sources say.

The chummy costars seemed to get along very well on the New York City set of Happy Hours, an upcoming film trilogy written by Katie, who is also appearing in and directing the dramedies.

"The spark between them is obvious and natural. It's been a blissfully happy reunion for them," an insider says. "When they're on set they stick to themselves mostly and are always deep in conversation.