Place the pie crust into a 20cm pie dish, trim off the excess, and crimp the edges if you like. Then put into the fridge until making the filling.
In a big mixing bowl, mix cream cheese and brown sugar for 1-2 minutes or until it becomes fluffy.
Add eggs to the previous mixture, one at a time, mix.
Next, add heavy cream, vanilla extract, peanut butter and sprinkle ground cinnamon, cardamom, nutmeg, flour, and salt. Mix well until combined.
Take out the pie dish from the fridge and pour the filling mixture over it.
Bake for 35-40 minutes maximum. The centre is supposed to be slightly jiggly. Let the pie cool down completely, then cover it and put it in the fridge for 4-5 hours to set.
Top the cinnamon pie with whipped cream and sprinkle some cinnamon on top then serve.
Notes
Keep leftovers in an airtight container in the fridge for up to 3 days.