In a large bowl, mix together crushed cookies, walnuts, and marshmallows. Spread half of mixture into crust. Drizzle evenly with half of caramel sauce and half of chocolate sauce. Top with remaining cookie mixture, and drizzle with remaining caramel and chocolate.
Bake in preheated oven for 10 to 15 minutes, until marshmallows are soft. Allow to cool to room temperature before serving.