Warm half & half in a microwaveable cup {about 30 to 1 minute} until steaming.

Combine the sugar and water in a small saucepan over high heat and bring to a boil without stirring, until amber brown. {Keep an eye on this, it can burn VERY quickly.}

Carefully whisk in warm cream until smooth and let cook for 1 minute {caramel will bubble & rise, so use a big enough saucepan so it does not overflow}.

Remove from the heat and whisk in the Nutella, corn syrup, salt and vanilla extract until smooth. Transfer to a heat safe bowl. Allow to cool until thickened, then transfer to jar or container where you will store.

Refrigerate.