Combine cream cheese and peanut butter. Mix on low speed of electric
mixer until smooth. Add powdered sugar and milk and continue to mix.
Blend in whipped topping on low speed. Pour into pie crust and freeze for
at least 8 hours before serving. Serve right out of freezer and drizzle
hot fudge topping warmed in microwave over each slice and garnish with
chopped nuts and whipped topping if desired.