Treacle tart

Sweet and comforting, Harry Potter's favourite pudding is a perfect example of culinary alchemy

- Dr Neil Buttery

It's no accident that treacle tart is beloved at Hogwarts, where students enjoy the best of British foods. This economical, comforting pudding was a cornerstone of high tea across the country in the 19th and 20th centuries. At its simplest, it consists of a pastry case filled with a mixture of golden syrup and stale breadcrumbs, its tooth-aching sweetness tempered by a spoonful of black treacle, lemon zest, mixed spice and sometimes cream, butter or eggs.

The 'treacle' is confusing, since the main ingredient is golden syrup. However, black treacle and golden syrup are the only two extant treacles of a range that varied in colour from a pale straw to almost black. In 1861, Mrs Beeton wrote of treacle in her