Step 1

In a large bowl, whisk together the pudding mix with the milk for 2 minutes. Set aside for 5 minutes to thicken.

Step 2

Line the bottom of a 9x13-inch pan with graham crackers (you may need to use halves or quarters to fill in spots).

Step 3

Spread half of the pudding over the layer of graham crackers. Add another layer of graham crackers on top of the pudding, then spread with the remaining pudding. Top with a final layer of graham crackers and spread the Cool Whip evenly over top. Crush 1 graham cracker into crumbs and sprinkle over the Cool Whip.

Step 4

Cover and refrigerate until cold and set, about 3 hours, or overnight. Leftovers should be stored, covered, in the refrigerator for up to 3 days.