In medium-sized saucepan over low heat, stir together brown sugar, cream and butter until butter is completely melted and ingredients are well combined.
Turn heat up to medium-high, stirring constantly until mixture begins to boil. Continue to stir constantly while mixture boils for one minute.
Remove from heat (continue to stir for another minute or the mixture may still burn to the pan).
Allow to cool 5 minutes then stir in vanilla and salt.
Allow to cool before serving.
Caramel can be stored in resealable container in fridge and re-heated.
To assemble cookie sandwiches, scoop Nutella ice crema on top of one cookie, drizzle with caramel sauce, and then sandwich between a second cookie. Serve immediately.