nutmeg

They were mixed with the go-to expensive spices of the day: cinnamon, nutmeg, mace, cloves, ginger and sugar.

Timothy Sharp, manager of Sparrow Coffee House in Cardiff, makes his own homemade syrup, adding spices like cloves, cardamom and star anise to the core PSL ingredients of ginger, cinnamon and nutmeg.

According to science journalist Alice Gray, from Cardiff, the scent of spices like cinnamon, nutmeg and ginger can therefore trigger happy, cosy and comforting memories.

Its key ingredients are espresso, "pumpkin spice flavour sauce" and steamed milk, topped with whipped cream and a spice blend of cinnamon, ginger, nutmeg and cloves.

It is not what you expect from an apple dessert, as there is no cinnamon, nutmeg, or other warming spice to give it that quintessential autumn flavor.