Prepare the Pudding: In a large mixing bowl, whisk together the instant vanilla pudding and 3 cups of milk until smooth. Let it sit for a few minutes until it firms up.
Fold in the Whipped Topping: Gently fold in the whipped topping into the pudding mixture until fully blended.
Layer the Graham Crackers: In a 9x13-inch baking dish, place a layer of graham crackers on the bottom.
Spread the Pudding Mixture: Pour half of the pudding mixture over the graham crackers, spreading it evenly.
Repeat the Layers: Add another layer of graham crackers, followed by the remaining pudding mixture, then top with another layer of graham crackers.
Make the Chocolate Glaze: In a small saucepan over low heat, melt the chocolate chips, butter, and milk, stirring constantly until smooth. Remove from heat and stir in the powdered sugar and salt until well combined.
Pour the Glaze: Pour the chocolate glaze over the top layer of graham crackers, spreading it out to cover completely.
Chill: Cover your cake with plastic wrap and refrigerate for at least 4 hours or overnight to allow it to set.
Serve: Once chilled, slice, serve, and enjoy the deliciousness!