In a large mixer bowl combine ice cream and 1/3 c . of peanut butter. Mix until smooth and then pour into prepared crust. Cover with wax paper and put into freezer. Combine 1/4 c. peanut butter and 1/4 c. corn syrup, blend well and spread on top of frozen pie. Return to freezer. Combine in a saucepan the remaining 1/4 c. corn syrup, unsweetened chocolate,(can use 2/3 c. semi sweet chocolate chips ,omit sugar, if using), sugar,milk,salt and vanilla. Cook stirring constantly about 5 minutes, or until thickened to make fudgy sauce. When ready to serve pie, defrost slightly and spoon some whipped topping, hot sauce and sprinkle of nuts on each serving. This is oh so to die for!