No Bake Pistachio Cheesecake Pie

Nilla Wafer or Graham Cracker crust ((I prefer the store bought))

boxes (3.4 oz each) pistachio instant pudding mix

half and half milk

bar (8 oz) cream cheese, softened

granulated sugar

tub (8 oz) Cool Whip, thawed

chopped pistachios ((for garnish))