Preheat
oven to 300 degrees F. Soften butter to room temperature.
Cream
butter until soft and fluffy. Beat in icing sugar.
Stir
in flour, salt, and cocoa, and mix well. If very soft,
chill in refrigerator for 1/2 hour.
Shape
into 1 inch balls and place on an ungreased cookie sheet
about 2 inches apart.
Flatten
balls with a fork.
Bake
for 20 - 25 minutes. Remove from oven, cool slightly
and remove from pan.