STEP 1 Make Oreo crust. Put Oreo cookies in a food processor, crumble it and then put in a medium bowl. Add softened butter and mix well. Place the mixture in a 9 inch springform pan and spread evenly. Set aside.

STEP 2 Make cheesecake filling. Put cream cheese, sugar, cinnamon, nutmeg and vanilla in a medium bowl and mix them at medium speed for about 30 seconds. Add pumpkin puree and mix some more until well combined. Leave aside. Pour heavy cream in a large bowl and mix at lower speed for about 30 seconds, then at maximum speed for a minute and a half. Pour pumpkin and cream cheese mixture in the bowl with heavy cream and mix them well. Spread the mixture evenly on the Oreo layer.

STEP 3 Make the topping. Put heavy cream and powdered sugar in a medium bowl and mix at a medium speed for about 30 seconds and then at a maximum speed for a minute. Spread evenly on the filling. Decorate with sprinkles and Oreo cookies.