Caramel Icing

Directions

1. 1
   Combine sugars and half and half; cook over medium heat at a rolling boil, stirring constantly for 6 to 7 minutes.
2. 2
   Remove from heat; add margarine and vanilla.
3. 3
   Stir until margarine melts, then set pan in ice water; stir until icing is of consistency to spread on cooled cake.
4. 4
   If too thick, add a few drops of milk.