Blend the cream cheese, sour cream, peanut butter and 1 cup of the icing sugar until smooth and creamy with a hand mixer. Sprinkle the chopped peanuts around the bottom of the pie crust and spoon the cheesecake filling on top, smoothing out the top and spreading the filling to the edge. Place a piece of cling film directly on top of the cheesecake and refrigerate until set, at least 3 hours.
Whisk together the double cream, cocoa powder and the remaining 3 tablespoons icing sugar in a medium mixing bowl until dissolved. Cover with plastic wrap and refrigerate along with the cheesecake.
When ready to assemble, whisk the double cream and cocoa powder mixture until medium peaks form. Place the cocoa whipped cream in to a resealable plastic bag and squeeze the icing toward one corner of the bag. Snip a small opening at the corner with the icing. Pipe the frosting in any pattern of your liking around the edge of the pie. Sprinkle the peanut butter chips and chocolate sprinkles on top of the whipped cream. If there is any leftover frosting, serve it in a bowl on the side.