Step 1

In a large bowl, whisk pudding mix and milk together for 2 minutes. Fold in 1/2 of the whipped topping.

Step 2

Cover the bottom of a 9 x 13 baking dish with a single layer of graham crackers. Add 1/2 the pudding mixture, spread into an even layer. Repeat with another layer of graham crackers and then the rest of the pudding. Top with remaining whipped topping.

Step 3

Cover and refrigerate overnight, or for at least 4 hours.

Step 4

Garnish with chopped pistachios if desired, slice, and serve.