Bring 1 1/2 cups cream, sugar, butter and corn syrup to boil in large heavy saucepan over medium-high heat, stirring until sugar dissolves and butter melts. Reduce heat to medium and boil gently until mixture is thick and deep amber, stirring often, about 35 minutes.

Remove sauce from heat. Whisk in remaining 1 cup cream (mixture will bubble vigorously). Strain into medium microwave safe bowl.

You can cool slightly and use now or cover and refrigerate up to 3 days. To rewarm, microwave in 15 second intervals.