Toffee is a chewy candy made by boiling sugar (or treacle) with butter or milk, then cooling the mixture so that it becomes hard and then cut into small, individual pieces of toffee. Toffee is a flavour of Bertie Bott's Every Flavour Beans and honey-coloured toffees were sold at Honeydukes
History
In 1992, Albus Dumbledore selected a golden-brown bean in the hope that it would be a toffee flavoured one, but it turned out to be ear wax instead. Also in 1992, on Harry Potter and Ron Weasley's journey to Hogwarts in the Flying Ford Anglia they snacked on a pack of toffees.
In 1995, Harry and Ron both received "dragon sized" Easter eggs from Molly Weasley that were stuffed full of toffees.