Make the crust
1-Preheat the oven to 350°F: Preheat the oven to 350°F. Spray a 9-inch pie dish with cooking spray.
2-Place the Oreo cookies in the bowl: Place the Oreo cookies in the bowl of a food processor and pulse until finely ground. Add in the melted butter and pulse until moistened. Press the mixture into the bottom and up the sides of the prepared pie dish. Bake for 10 minutes, or until fragrant and set. Let cool completely on a wire rack.

Make the filling
3-In a microwave-safe bowl, heat the chocolate: In a microwave-safe bowl, heat the chocolate on high in 30-second intervals, stirring between each interval, until melted and smooth. Let cool.
4-In a large bowl, use an electric: In a large bowl, use an electric mixer fitted with the whisk attachment to beat the cream until soft peaks form. On medium speed, gradually add the caramel and continue whipping until medium-stiff peaks form. Gently fold in the cooled melted chocolate until combined. Pour into cookie crust and cover with plastic wrap. Refrigerate for at least 6 hours.

Make the topping
5-In a large bowl, use an electric: In a large bowl, use an electric mixer fitted with the whisk attachment to beat the cream until thickened. Add the peanut butter, sugar, and vanilla and beat on high speed until soft peaks form. Be careful not to overbeat.
6-Spread the cream evenly over the mousse: Spread the cream evenly over the mousse layer. At this point you can refrigerate overnight if desired.
7-Just before serving, drizzle with as much: Just before serving, drizzle with as much caramel sauce, melted chocolate, and melted peanut butter as desired.