2 cups granulated sugar
12 tablespoons unsalted butter, at room temperature, cut into pieces
1 cup heavy cream, at room temperature
1 tablespoon fleur de sel or Maldon sea salt flakes
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 high-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. If the sugar gets stuck to the whisk, you can switch to a wooden spoon.
Remove the pan from the heat and slowly pour in the heavy cream. Whisk until cream is incorporated and caramel is smooth. Whisk in the fleur de sel or Maldon sea salt flakes.
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.