Treacle tart is something of a British classic. Frugal and filling, it also has a delicious decadence, its humble ingredients coming together in a dessert with much greater elegance than the sum of its parts. Loved by generations of Brits, this syrupy tart achieved global recognition a few years back when chosen as the favourite pudding of a certain bespectacled wizard – for Harry Potter to choose treacle tart over Fizzing Whizzbees, Cauldron Cakes and Bertie Bott’s Every Flavour Beans, it must be something pretty special.