In a large bowl, cream the cream cheese until smooth with an electric beater. Once the cream cheese is completely smooth, add the pumpkin, sugar and pumpkin spice. Continue to beat until smooth. In a separate bowl, with an electric mixer, whip the the whipping cream until stiff peaks form. Add the sugar and beat for another few seconds. Fold a cup of the whipping cream into the pumpkin mixture. Save any extra to serve on the top. Pour the pumpkin mixture into a prepared graham cracker crust. Keep pie in the fridge until ready to serve. Serve with caramel topping, more whipped cream and chopped nuts (optional) as a garnish.