In a large mixing bowl, whisk together the instant vanilla pudding mix and cold milk until smooth. Allow it to sit for a couple of minutes until it thickens.
Gently fold the thawed Cool Whip into the pudding mixture until fully combined and smooth.
In a 9x13 inch baking dish, lay a single layer of graham crackers on the bottom.
Spread half of the pudding mixture over the graham crackers, smoothing it out evenly.
Add another layer of graham crackers on top of the pudding layer.
Pour the remaining pudding mixture over the second layer of graham crackers, spreading it evenly.
Top with a final layer of graham crackers.
Microwave the chocolate frosting for about 10-15 seconds to soften it, then spread it evenly over the top layer of graham crackers.
Cover the dish with plastic wrap and refrigerate for at least 4 hours, or overnight, to allow the flavors to meld and the graham crackers to soften.
Slice into squares and serve chilled. Enjoy your delicious no-bake eclair cake!
