Crush graham crackers into fine crumbs using a food processor or by placing them in a sealed bag and rolling with a rolling pin.

In a bowl, mix the graham cracker crumbs with melted butter until combined. Press the mixture firmly into the bottom of a 9x13-inch baking dish to form the crust. Chill in the refrigerator for 15 minutes.

In a large bowl, beat the softened cream cheese, powdered sugar, and vanilla extract until smooth and creamy. Spread the mixture evenly over the crust.

In another bowl, whisk together the pistachio pudding mix and cold milk for about 2 minutes, until thickened. Gently spread the pudding over the cream cheese layer.

Spread the whipped topping evenly over the pudding layer.

Sprinkle chopped pistachios over the top and garnish with maraschino cherries if desired.

Cover and refrigerate for at least 4 hours, preferably overnight, before serving.