Wash the strawberries, remove the green and quarter the strawberries.
Place in a saucepan and add the vanilla sugar, preserving sugar and strawberry syrup. Bring to a boil and then simmer for about 5 minutes.
Blend finely with a hand blender.
Immediately pour into sterilized jars and turn them upside down for 5 minutes.
Then invert again and let cool completely.
Preparation Tip:
If you want a particularly fine strawberry jam, strain the jam before bottling.