In a large bowl, whisk together the vanilla pudding mix and cold milk for about 2 minutes until thickened.
Gently fold in the whipped topping until smooth.
In a 9x13-inch baking dish, layer graham crackers to cover the bottom.
Spread half of the pudding mixture over the crackers.
Add another layer of graham crackers, then spread the remaining pudding mixture on top.
Finish with a final layer of graham crackers.
Microwave the chocolate frosting for 15-20 seconds to soften, then spread evenly over the top layer of crackers.
Cover and refrigerate for at least 4 hours or overnight for best results.
Slice, serve, and enjoy!