1)

Add the sugar and water to a 3-quart heavy bottomed pot; stir just slightly so it's combined and sits in a flat even layer, and try to avoid it going up the sides of the pot.

2)

Warm pot over medium heat and cook until the sugar dissolves, turns from cloudy to clear, and starts to bubble. At this point, do not stir again.

3)

Continue cooking, without stirring, until the mixture thickens and turns a deep gold color like honey (this can take anywhere from 8-15 minutes).

4)

Carefully add the butter and whisk until completely melted. (The caramel will bubble up rapidly, so be careful and continue to whisk.)

5)

Remove the pot from the heat. Slowly pour in the heavy cream, whisking continuously until all of the cream has been incorporated.

6)

Whisk in the vanilla and salt.

7)

Set aside to cool in the pot for 10 minutes.

8)

Pour into a lidded glass jar and allow to cool completely. (The caramel will be liquid at first, but will thicken up and solidify into a chewy texture as it cools.) Once completely cooled, store in the fridge because of the dairy. Reheat to use again.