Place sugar in iron skillet over medium-low heat. Stir it constantly as it melts. If a strong caramel flavor is desired, burn the sugar slightly.
Slowly pour boiling water in sugar. Note: sugar and water will react violently, add water slowly. Cook the mixture until it is the consistency of maple syrup. This syrup may be kept indefinitely in a closed jar or bottle. It may also be flavored with rum.
When mixture has reached the desired consistency, add warm cream and cook until slightly thickened. Remove from heat and chill.