Add the sugar and water to a light-colored saucepan set over medium to medium-high heat. Stir just until the sugar is dissolved.

Then cook the caramel at a rapid simmer for an additional 5-6 minutes. If not at a rapid simmer, turn the heat up just a bit. Only swirl the pan occasionally, no more stirring. The color will change from clear to deep amber - watch the caramel closely as the color will change quickly during the last couple minutes.

Immediately when the caramel reaches a deep amber color (similar to the color of a dark honey...see my photos), remove it from the heat. Then slowly drizzle in the warm cream. Be careful as it can splatter.

Next add the butter and salt. Stir gently until the butter has melted.

Transfer the finished caramel sauce to a heat-safe container and store it in the fridge until chilled. This can be made up to a few days in advance of making the ice cream.

Add the heavy cream to the bowl of a stand mixer fitted with the paddle attachment. Beat on medium-high speed for 3-5 minutes, or until stiff peaks form.

Next add the sweetened condensed milk, vanilla, and ¼ cup of the salted caramel sauce. Fold the mixture together until it is well combined.

Pour half of the ice cream base into a 9x5 loaf pan. Add 3 tablespoons of caramel sauce on top. Next add the remaining ice cream base and finally top with another 3 tablespoons of caramel sauce.

Quickly swirl the caramel into the ice cream and then wrap the loaf pan tightly in plastic.

Freeze the ice cream until fully set - at least 8 hours, although I highly recommend overnight.

Serve with the remaining salted caramel sauce if desired.