First make sure you have all of the ingredients ready. Once you start the caramel sauce you have to pay close attention so you don't burn it.
To begin, heat the sugar over medium heat in the bottom of a heavy 2-3 quart saucepan.
When the sugar starts to melt, start whisking the sugar. The sugar will clump up, but keep whisking. It will continue to melt. When the sugar is melted, stop whisking. You can swirl the pan to move the sugar around. Continue cooking the sugar until it reaches a deep amber color. Make sure you watch the pan very closely. This is where it is easy to burn the caramel.
As soon as the sugar reaches the dark amber color, carefully add the butter. Whisk until butter is melted. The caramel will bubble up rapidly, so be careful and continue to whisk.
Remove the pan from the heat and slowly pour in the heavy cream. Whisk until cream is incorporated and caramel is smooth. If you like, this is where you would whisk in a pinch of sea salt for a salted caramel.
Let the caramel sauce cool for about 10 minutes in the pan. Pour the caramel into a large jar and cool to room temperature. Put the salted caramel sauce in the refrigerator. Store the salted caramel sauce in the refrigerator for about a month.
Notes
Caramel will thicken alot once refrigerated, but you can reheat the amount you need in a small sauce pan for dipping or drizzling, or just add a cold spoonful to a hot latte!