Melt the margarine. First stir in the milk and then the remaining ingredients. Beat with the hand blender (whipping disk). Pour into a jam jar and store in the refrigerator.
I don`t know how long the Nutella substitute will last. With us it is used up after a week at the latest.
Tip:
For the vanilla sugar, I mix 100g Sukrin with some ground Bourbon vanilla in advance.