First you whip the 200 g whipped cream, but not too hard (do not beat too long), otherwise you cannot mix the whipped cream with the Nutella later. At the same time, heat the Nutella in the microwave over low heat, being careful not to burn it.
As soon as the Nutella cream is nice and liquid, you can stir it into the whipped cream. Then add milk, cocoa powder and vanilla sugar and stir everything vigorously.
Then you put the mixture in the ice cream machine. When the mass has set, you can still put it in the freezer so that it hardens there.
If you don`t have an ice cream maker, you just put the mixture in a mold, put it in the freezer and stir every 30 minutes.