Cut 5 quinces into quarters (or as many quinces as you like, really)
Make a syrup of 6c hot water, and 1c sugar, and stir till sugar has dissolved.
Pack quinces into a roasting dish, and sprinkle over a stick of cinnamon, cracked up, and 1t vanilla. Pour over the hot syrup.
Bake 150C for 1.5hrs covered with tinfoil, then remove the foil and bake another 1.5hrs. Quinces and syrup should be deep red.
Pack into hot jars, with the liquid right up to the top, and seal.