Emily and Melissa Elsen, the sisters behind famed pie shop Four & Twenty Blackbirds, use this simple caramel sauce as a key ingredient in their Salted Caramel Apple Pie (recipe available in Panna's "How to Make Pies" class). But it tastes just as great with ice cream, waffles—or even a spoon!
Whisk sugar and water together in a medium saucepan, and cook over medium-low heat until the sugar is just dissolved. Add the butter and bring to a slow boil. Continue stirring over medium heat until the mixture turns a deep, golden brown color, almost copper.
Turn off heat; immediately but slowly add the heavy cream (use caution, as the mixture may bubble up rapidly). Whisk the final mixture thoroughly to combine, and set aside to cool. Makes about 2 cups.
Caramel Sauce can be made several days in advance. Cool, then store in the refrigerator in an airtight container; bring to room temperature before using.