In a large bowl cut butter into cake mix until mixtureresembles coarse crumbs. Press into a greased 9 by 13 cake pan. Bake at 350 for15-18 minutes or until set. Beat cream cheese and powdered sugar, fold in 1 cup whipped topping.
Spread overcooled crust, refrigerate until set. In a bowl whisk together milk and both puddings.
Let stand for 5 minutes or until slightly thickened.
Spread over cream cheese mixture.
Top with 3 cups whipped topping.
Sprinkle with chocolate shavings.
Refrigerate at least 2 hours before serving. Delicious served withice cream.