In a large bowl, combine all pkgs. of pudding mix with milk, mixing until smooth. Add COOL WHIP, using an electric mixer until all ingredients are blended together.
In a glass casserole (9" by 12"), add one flat layer of graham crackers. Pour half of pudding mixture on top of crackers, smoothing until even. Add one more layer of graham crackers, and on top of that the remaining pudding mixture.
Heat frosting (either in microwave or stovetop) until completely melted. Add over top of the pudding, spreading over entire top.
Refrigerate for 4 hours, or until graham crackers aren't crunchy anymore.