I’m alive,” mutters 70-year-old Mahin (Lili Farhadpour) through the blanketing layers of sleep. It’s a daily ritual. She finally dozes off after a restless night, only to be woken by one of her friends phoning to check up on her. Mahin barely sees them now. The once weekly get-togethers have become yearly; the gossipy conversation is, of late, dominated by discussions of bowel polyps and kidney failure. Widowed for 30 years and alone since her daughter and grandchildren emigrated, in her quiet home on the outskirts of Tehran, Mahin feels the ache of isolation on a daily basis. She’s alive. But is she living?

Mahin decides to take control of her fate and sets out to revamp her love life. Before long, her eye is caught by taxi driver Faramaz (Esmaeel Mehrabi). Throwing caution to the winds, she engineers a night to remember, filled with music, dance and brain-bruising quantities of wine. But plans have a way of going awry in this lovely, intimate, tragicomic tale of late-blooming love in the shadow of Iran’s repressive regime.

In its gentle way, this is a subversive piece of film-making. Its directors, Maryam Moghadam and Behtash Sanaeeha, were prevented from travelling to Berlin in February for the film’s world premiere after the Iranian authorities confiscated their passports, having taken issue with scenes of hijab-free boozing, dancing and a terrific sequence in which Mahin faces down the “morality police”. Perhaps more radical than the censor-bating, though, is the fact that My Favourite Cake trains its lens on lonely, ordinary older people – a demographic all too frequently invisible to film-makers the world over. A rare delight.

• In UK and Irish cinemas