Pour the sugar into a medium heavy-bottomed saucepan and gently shake to level. Set over medium-low/low heat on a small burner and do not stir. After 10-15 minutes, the edges of the sugar will start to caramelize and turn brown. When you can see a small bit of caramelization on the edges, use a non-stick heat-proof utensil to pull the edges toward the center. As the caramel continues to cook, stir gently to moisten and dissolve the dry bits of sugar. Cook the caramel to a very deep, clear amber color, about 30 minutes total cooking time.

During the last 10 minutes or so of cooking, heat the cream, butter, and salt over low heat in a separate saucepan until it begins to simmer. When the caramel is finished, drizzle the warm cream mixture into the caramel and stir together. If the caramel seizes (solidifies) don’t panic! Simply continue to stir and cook over low heat until the caramel melts again.

When the sauce is finished, enjoy right away or store. To store, pour into a jar and allow to cool to room temperature before sealing and storing in the fridge. Keep for up to a month in the refrigerator, and dip the jar in warm water to thaw.