In a double-boiler pour 1 (12 oz. bag semi-sweet chocolate chips) and 1 pint cream. Allow to melt, then stir well. Remove from heat. Mix in 2 cups powdered sugar. Frost cooled cake immediately. Will cover and fill a 9 inch, two-layer cake, with some leftover to eat by the spoonful or on vanilla wafers/graham crackers/saltines...
Refrigerate until serving; bring to room temperature 30 minutes before serving.