In a heavy medium saucepan, combine the sugar and water and simmer over high heat without stirring until the sugar dissolves. Stir lightly and lower the heat to moderate. Simmer undisturbed until a deep amber caramel forms, about 10 minutes. Remove from the heat and gently stir in the cream until the sauce is smooth. Let cool to room temperature.
The sauce can be refrigerated for up to 3 days. Let return to room temperature before serving.