How to Make It
Stir together cereal, finely chopped peanuts, and butter in a medium bowl. Press mixture into bottom and up sides of a lightly greased 9-inch glass pie plate. Freeze until solid, 15 to 30 minutes.
Microwave peanut butter in a small microwave-safe bowl on HIGH until melted and smooth, about 30 seconds. Let stand at room temperature 10 minutes, stirring occasionally.
Place ice cream in the bowl of a heavy-duty stand mixer; beat on medium-low until smooth, about 30 seconds. Drizzle peanut butter into ice cream, beating on low just until incorporated, about 30 seconds.
Spread ice cream mixture into frozen pie shell. Cover and freeze until firm, 8 hours, or up to 24 hours.
Before serving, remove pie from freezer, and leave out at room temperature 10 minutes. Meanwhile, beat cream and vanilla with an electric mixer on medium-high speed until foamy, about 30 seconds. Gradually add powdered sugar, beating until soft peaks form, 30 seconds to 1 minute. Spread whipped cream evenly over pie. Drizzle with fudge topping, and sprinkle with coarsely chopped peanuts.