Fudge Frosting - cooking recipe

Ingredients

1 lb. unsifted powdered sugar
1/2 c. dry cocoa
1/4 tsp. salt
1 tsp. vanilla
7 Tbsp. boiling water
6 Tbsp. soft butter

Preparation

Mix powdered sugar, cocoa and
salt
thoroughly,
so no lumps of cocoa can be seen.
Add
vanilla
and
boiling water. Stir smooth.
Add soft, not melted, butter
and
stir
or beat until smooth, just stiff enough to
spread.
The
frosting may seem too thin at first, but it
stiffens
as it cools.
(If it should get too thick while spreading, stir
in
a few drops of hot water.) Yields enough to cover
two
(8
or 9-inch) layers generously.