Heat sugar on moderately high heat in a heavy-bottomed saucepan.

As the sugar begins to melt, stir vigorously with a whisk or wooden spoon. As soon as sugar comes to a boil, stop stirring. You can swirl the pan a bit if you want, from this point on.

As soon as all of the sugar crystals have melted (the liquid sugar should be dark amber in color), immediately add butter to the pan. Whisk until the butter has melted.

Once the butter has melted, take the pan off the heat. Count to three, then slowly add the cream to the pan and continue to whisk to incorporate. Note than when you add the butter and the cream, the mixture will foam up considerably.

Whisk until caramel sauce is smooth. Let cool in the pan for a couple minutes, then pour into a glass mason jar and let sit to cool to room temperature.

Store in the refrigerator for up to 1 month. Warm before serving.

Enjoy the sauce topping over your favorite ice cream and drizzle over brownies and cheese cakes.