In a pot with a candy thermometer attached to the side, combine sugar and water. Allow mixture to cook to 340 degrees F (sugar will be an amber color at this temperature) over medium-high heat. This will take approximately 20 to 25 minutes.
Remove browned sugar from stovetop and carefully whisk in the butter until melted. (Caution: Mixture is very hot and will give off hot steam that can burn you.)
Add cream and continue to whisk until combined. Let cool for approximately 20 minutes. (Caution: Do not attempt to taste the caramel until it has cooled completely!)