Amaretto is an Italian liqueur distilled since as early as the 15th century. Directly translating as 'little bitter' it has a distinctive almond flavour and traditionally was flavoured by bitter almonds. Modern incarnations see it prepared from apricot stones, peach stones and almonds. Enjoyed straight or as part of a blended cocktail, it is also a key ingredient in desserts such as tiramisu, coffees and cakes.
Given its versatility, it's no surprise that it makes such a popular e-liquid flavour. Its overall sweetness means that it can be a bit rich vaped on its own, but you'll often find amaretto combined with tobacco to cut through the dark, smoky notes. It also works very well with fruits like berries thanks to its nutty taste.