Place pecan sandies cookies in food processor and process until sand like texture, add in 1 cup butter until well incorporated. Press into 9" pie plate. spread 1 cup of peanut butter on bottom of crust. Pour chocolate chips in a small glass bowl and set aside. In small sauce pan heat heavy cream to a boil then pour over chocolate chips. Let sit for 1 min then whisk until cream is completely incorporated into chocolate. Pour into pie crust covering the peanut butter. Place pie crust into freezer.
In heavy saucepan, dissolve cornstarch in water; stir in sweetened condensed milk and egg yolks. Cook and stir until thickened and bubbly. Remove from heat and add banana extract, 2 tablespoons butter and 1/2 cup peanut butter.
Take pie crust out of freezer. Slice 2 bananas into pie crust creating a layer of bananas. Pour caramel ice cream topping over bananas. Mash remaining banana and add to peanut butter custard. Pour custard into pie crust and refrigerate for at least 4 hours or until set. Top with whipped topping and serve cold.