01 - Combine sugar and water in a medium saucepan over medium heat. Stir gently until sugar dissolves, then allow mixture to boil without stirring until it turns a deep amber color, about 5 to 7 minutes.
02 - Remove saucepan from heat. Whisk in cubed butter until fully melted, then slowly add heavy cream while whisking continuously. Stir in sea salt if desired. Let caramel cool to room temperature.
03 - In a large bowl, combine cold milk, cold heavy cream, sugar, and vanilla extract. Whisk together until sugar dissolves completely.
04 - Pour the cooled caramel sauce into the cream mixture and whisk thoroughly until fully incorporated.
05 - Transfer the combined mixture into a freezer-safe container. Cover and freeze for 4 hours, stirring every hour to achieve a lighter texture, or churn in an ice cream maker according to manufacturer’s instructions for optimal consistency.
06 - Scoop the frozen treat into serving glasses or bowls. Add whipped cream, gluten-free chocolate shavings, and a sprinkle of ground cinnamon if desired.