Ima'S Chocolate Icing (Old Fashioned)

Directions

1. 1
   Mix cocoa and sugar; add milk.
2. 2
   Stir until dissolved.
3. 3
   Put on stove.
4. 4
   When mixture comes to a boil, cover pot and boil hard for 1 minute.
5. 5
   Remove from heat.
6. 6
   Add vanilla and butter.
7. 7
   Beat until cooled.
8. 8
   Spread on cake.