1. First sterilize the glass jars* and lids – either by boiling them in plenty of water or heating them in the oven. Be careful with the lids, they might not withstand the same heat as the glass jars. Set aside and let dry.

2. Wash the damson plums, dry them, half them and pit them. Cut the halved plums once again in half and add them to the saucepan you want to cook them in later on. Add the xylitol, vanilla powder, and ground cinnamon as well and mix everything. Cover and let sit for about 1 hour.

3. Add the gelling powder (Gelierfix) and lemon juice, then purée everything using an immersion blender*. If you want some larger pieces, purée only briefly.

4. Bring the mixture to a boil, then let it boil vigorously for about 4–5 minutes while stirring constantly. Do a gelling test (using a small plate) – if the jam sets quickly, it is ready to be canned. If not, simply cook it a tiny bit longer.

5. Transfer the jam to the prepared glass jars and seal them tightly immediately. There is no need to turn the jars upside down. Let them cool completely. Store the jars in a cool, dark place (e.g. basement). If you worked with clean equipment, the unopened jam should keep for 1–2 years. Once opened, store in the fridge and consume within 2–6 weeks.