In a mixing bowl, combine graham cracker crumbs and melted butter until well coated. Press the mixture into the bottom of a 9x13-inch baking dish to form a firm crust. Chill in the refrigerator while preparing the next layers.
In a separate bowl, beat cream cheese, powdered sugar, and vanilla extract until smooth. Fold in 1 cup of whipped topping and mix gently. Spread evenly over the crust.
In another bowl, whisk together the pistachio pudding mix and cold milk for about 2 minutes until thickened. Spread the pudding mixture over the cream cheese layer.
Top with the remaining whipped topping, smoothing it over the pudding layer.
Refrigerate for at least 4 hours, or overnight for best results, to allow the layers to set.
Before serving, sprinkle chopped pistachios on top for extra crunch and flavor. Slice and enjoy!