Simmer all the spices and the vanilla pod (but not the extract if you are using it) with the apple juice on a very low heat for at least an hour. Keep the pan covered with the lid ajar - you don't want all the moisture to evaporate, but you do want the juice to reduce a little. If using vanilla extract, add it after you have finished simmering as the flavour is more fragile and will disappear in a long simmer. This spiced syrup will keep for at least a week in the fridge.

When you want mulled cider, gently heat the syrup and cider in a pan until it is drinking temperature. Do not boil the cider as this will cause the alcohol to evaporate.

Serve with pieces of sliced apple or citrus fruit.