Place the sugar and water in a small pot and put it on the stove over medium heat. Let it cook without stiring, for about 10 - 12 minutes until the sugar dissolves and turns a bit yellowish in color.
Meanwhile, place the cream in a heat resitant bowl and put it in the microwave for 12 minutes so it heats up a little.
When the 12 minutes have passed, carefully add in the cream, and mix using a rubber spatula and cook for 2 to 3 minutes until a soft caramel forms.
Take off the heat, then mix in the butter with a pinch of salt and mix using the same spatula to get a smooth caramel. Serve while still hot and store in a container with a lid for up to 1 month.