Ben Miller, Celia Imrie, Anne-Marie Duff, Sadie Frost and Joan Collins have joined the cast of Amber Entertainment’s fantasy actioner “Molly Moon.”Dominic Monaghan, Lesley Manville and Emily Watson had been announced previously for “Moon” and Raffey Cassidy will star as Molly. Christopher N. Rowley (“Bonneville”) directs with Georgia Byng, Lawrence Elman and Ileen Maisel producing. Pic is an adaptation of Byng’s fantasy novel about an orphan who learns the art of hypnosis. The script was penned by Rowley and Byng with a polish by Chris Hurford and Tom Butterworth. Production began Thursday in London for a seven-week shoot. “Moon” is financed through equity and U.K. tax credits. Camela Galano’s Speranza 13 banner will be selling territories at the American Film Market. “Harry Potter” producer David Heyman acquired feature rights to the first book a decade ago, but that option lapsed, and New Line considered the property five years later. Former New Line exec Maisel began discussing the film project with Byng a few years ago before acquring the rights. Amber’s in post-production on “Romeo and Juliet,” starring Hailee Steinfeld and Douglas Booth, and produced thriller “The Frozen Ground,” starring Nicolas Cage and John Cusack, with Emmett/Furla Films.