Chocolate Mocha Punch

I found this years ago while digging through some old recipes of a friend. It is the most requested punch I have ever made.

7 cups water
1/4 cup instant coffee (I use decaf for the kids)
2 cups nonfat dry milk
1/2 cup granulated sugar
Dash of salt
1 quart chocolate ice cream, softened
Cool Whip

Heat 3 cups of water to boiling; dissolve instant coffee in water, stir in the dry nonfat milk, sugar, and salt. Mix until dissolved. Add the other 4 cups of water. Refrigerate until chilled - 3 to 4 hours.
Place ice cream in a punch bowl. Pour chilled coffee mixture on ice cream; swirl ice cream throughout coffee mixture. Top punch with mounds of Cool Whip.