Rinse the quetsche plums under fresh water, pat dry with a kitchen towel, halve, and remove pits. Peel the apples, core them, and slice thinly.
In a large earthenware dish, combine the fruits with sugar, lemon juice, star anise, and vanilla pods split lengthwise.
After 1 hour of maceration, transfer to a jam pot, bring to a boil, and simmer for 1 minute. Return to the dish, cover with parchment paper, and refrigerate for 12 hours.
The next day, boil again for 5 minutes, stirring gently and skimming foam. Remove vanilla pods and star anise.
Immediately ladle hot jam into sterilized jars, seal, and let mature for at least 1 week before enjoying.
Recipe from Christine Ferber's renowned book: My Jams.
