1 cup heavy cream
1 1⁄2 cups sugar
2 1⁄2 tbsp. unsalted butter
1 tsp. kosher salt
In a medium saucepan, combine the cream with the butter and salt. Place over medium heat, and cook, stirring, until the butter has melted, 3 to 4 minutes. Remove the pan from the heat and keep warm.
In a small saucepan, heat the sugar over high, and cook, stirring occasionally, until the color of dark amber, about 8 to 10 minutes.
Remove the pan from the heat and then pour the warm cream into the caramel. Stir until the caramel dissolves, and then serve or let cool completely. Store cooled caramel in an airtight container in the refrigerator for up to 2 weeks.