In a saucepan over medium-high heat, combine sugar and water. Bring to a boil and let cook until mixture turns golden (do not stir during this time). Watch carefully, it might seem like it’s taking a long time, but then it will get dark quickly. Don’t let it burn!
Once mixture is deep golden brown, remove from heat source and stir in heavy cream, butter, and salt.
Keep in an airtight container in the refrigerator. Rewarm when ready to serve!