For the blueberry-vanilla jam, wash the jars thoroughly with hot water. Put the blueberries in a pot and heat, add sweetener and stir well.
Finely puree the fruit with a blender. Whom pieces in the jam do not bother, can also just mash the fruit.
Then mix 1 heaped tsp (equivalent to 4 g) agar agar with cold water and let it swell. After 2 minutes, mix it into the hot fruit pulp.
Add vanilla powder and bring the jam to a boil and simmer gently for about 3-5 minutes, stirring constantly. Then pour the fruit mixture into the prepared glasses.