Mix pudding and milk. Beat for 2 minutes and then fold in the Cool Whip. Pour into a buttered 13x9 dish that your have already layered with the graham crackers. Add another layer of crackers. Top with another layer of pudding and then another layer of graham crackers. Spread chocolate frosting over the last layer of graham crackers. Let stand overnight in the refrigerator.
Combine the sugar, salt, cocoa, and milk. Boil for 1 minute. Remove from the heat and add butter and vanilla. Beat until smooth and thick enough to spread. You may substitute one container of store bought (Pillsbury, Betty Crocker, etc) frosting for this recipe.