Cook the sugar and water in a saucepan, stirring, over low heat until the sugar has dissolved. Continue cooking, without stirring, until deep golden brown.
Bring the cream to a boil in a separate saucepan. Remove the caramel from heat and stir in the cream. Return to medium heat for 3 minutes, beating constantly. Remove from the heat and add the butter. Serve warm. Yield: 2 cups.