Helen's Soft Chocolate Frosting

Description
Here is a good, fast-cooked icing.

Helen's Soft Chocolate Frosting by Helen Monahan from Recipes for Better Nutrition During Cancer Treatment by the National Cancer Institute, public domain government resource—original source of recipe

Ingredients

 * ½ cup white sugar
 * ½ cup brown sugar
 * 3 heaping tbsp cocoa
 * 3 heaping tbsp cornstarch
 * 1 cup milk
 * 3 tbsp margarine

Directions

 * 1) Mix first four ingredients together in saucepan until well blended.
 * 2) Gradually add milk.
 * 3) Add margarine.
 * 4) Cook over medium heat, stirring constantly until thick and smooth (you may need to remove from heat occasionally to prevent sticking or lumping).
 * 5) Ice cake while the frosting is still warm.
 * 6) Ices two 9-inch layers.
 * 7) Recipe can easily be cut in half for a single layer cake or cupcakes.