Chocolate Velvet Icing

Directions

1. 1
   Combine sugar, cornstarch and salt in medium saucepan.
2. 2
   Stir until well blended.
3. 3
   Add boiling water, stir until well blended. Put on stove and cook until mixture thickens, stirring constantly. Add chocolate and butter to mixture, continue cooking and stirring until chocolate and butter melts.
4. 4
   Remove from heat.
5. 5
   Add vanilla, stirring constantly. Let cool a little.
6. 6
   Spread over cake.