1. Split the vanilla pod lengthwise into two halves and scrape out the seeds.
2. Mix scraped seeds with sugar, water and vinegar in a kettle.
3. Cook it for a few minutes. Then add the rosehip.
4. Simmer it for about 20 minutes. 5 min before finished add the hazelnuts.
5. Pour the mixture into clean, scalded jars. Place the lid on.
6. Store in a cool, dark place.