Place a loaf pan in your freezer to chill.
Pour heavy cream into a large mixing bowl. Using an electric mixer, beat the cream on low until it starts to thicken. Increase the speed to high and beat the cream until stiff peaks form.
Using a rubber spatula, gently fold in the sweetened condensed milk, ⅓ cup caramel sauce, vanilla and salt.
Scoop one-third of the ice cream mixture into the frozen loaf pan. Next, drizzle one-third of the remaining caramel sauce over the ice cream. Top with half the remaining ice cream, then half the caramel sauce. Finally, layer the last of the ice cream on top, then drizzle with the remaining caramel. Use a table knife to gently swirl the caramel throughout.
Place the ice cream in the freezer, making sure the pan is level. Once frozen, cover in plastic to seal. The ice cream will be firm in about 6 hours.
Serve topped with additional caramel sauce if desired.