Prepare brownies according to package directions, using a greased 13-in. x 9-in. baking pan. Cool completely.
In a large bowl, beat cream cheese and sugar together for 2 minutes.
Fold in 2 cups of Cool Whip and spread over cooled brownies.
In another bowl, add the milk and pudding mix and beat until smooth. Refrigerate for 5 minutes then spread over the cream cheese layer.
Spread with remaining whipped topping over the pudding layer. Refrigerate until serving. Top with shaved chocolate id desired before serving. Makes 12-15 servings.