Combine ¼ cup corn syrup, brown sugar, and margarine in medium size saucepan. Cook over low heat, stirring occasionally, until mixture begins to boil. Remove from heat. Add rice crispy cereal, stirring until well coated.
Press evenly in 9 inch pan to form crust.
Put in freezer until crust is firm.
Stir together peanut butter, fudge topping, and 6 tbsp. corn syrup.
Spread ⅔ of the peanut butter mixture over crust. Freeze until firm.
Allow ice cream to soften slightly. Spoon into frozen crust, spreading evenly. Freeze until firm.
Let pie stand at room temperature about 10 minutes before cutting. Warm remaining peanut butter mixture and drizzle over top.