In a large mixing bowl, whisk together the vanilla pudding mix and cold milk until thickened. Fold in the whipped topping until fully incorporated.
In a 9x13-inch baking dish, arrange a single layer of graham crackers to cover the bottom completely.
Spread half of the pudding mixture over the graham crackers, smoothing it into an even layer.
Add another layer of graham crackers on top of the pudding, followed by the remaining pudding mixture. Top with a final layer of graham crackers.
In a microwave-safe bowl, combine the chocolate chips, butter, corn syrup (or honey), and milk. Microwave in 20-second intervals, stirring each time, until smooth and glossy.
Pour the chocolate glaze over the top layer of graham crackers, spreading it evenly with a spatula.
Cover the dish with plastic wrap and refrigerate for at least 4 hours, or overnight, to allow the layers to set.
Slice into squares and serve chilled. Enjoy!