In a heavy-bottomed pan over medium heat, cook condensed milk until golden brown in colour, stirring constantly for about 10-12 minutes. The caramel will turn thicker as it cooks, but constant stirring will ensure an even colour.
Remove caramel from heat and whisk in cream and milk a little at a time, being careful for steam that comes off the hot caramel when cream is added. Add salt. Stir in vanilla extract and cool mix completely.
Prepare ice cream in an ice cream maker, following the manufacturer’s instructions. Serve immediately for soft-style ice cream, or freeze until ready to use.