Tip the peaches and sugar into a large bowl and toss to combine. Leave to macerate, uncovered at room temperature, for 3-4 hrs, or until the fruit has softened slightly and is juicy. Meanwhile, put a small plate or saucer in the freezer.

Transfer the peaches to a large, wide pan. Add the lemon juice and bay, if using (along with the vanilla seeds and pod, if using, instead of the amaretto). Cook over a low heat for 5-10 mins until the sugar has dissolved, then turn up the heat to medium-high and simmer for 30-40 mins until it reaches 105C on a sugar thermometer. To check the jam is ready, spoon a little onto the cold saucer – it should set quickly, and when pushed with your finger, it should wrinkle and not flood the gap left behind.

Remove the jam from the heat and add the amaretto, if using. Skim any foam from the surface, then leave to rest in the pan for 20 mins. Decant into sterilised jars (find out how to sterilise jars), seal and chill until needed. Will keep chilled for three months, or for a week once opened.