Place a medium-sized saucepan over medium heat.
Pour in 1 cup sugar gradually, adding 1/4 cup at a time. Wait until the sugar is mostly dissolved, then add in the next bit of sugar. As the sugar melts it will slowly deepen in color.
Stir occasionally until the sugar is fully dissolved and has become a deep amber color, then turn off the heat.
Slowly mix in 6 Tbsp of butter (2 Tbsp at a time) then stir in 1/4 cup of heavy cream and 1/4 tsp salt. The mixture will be thin but will thicken as it cools.
Pour into a separate container, then place in the fridge to cool and/or store. When you're ready to use it, heat the caramel in the microwave in short 15-second intervals until it's a more workable consistency.
