Preheat the oven to 350 F. Spread all the pistachios onto a baking pan and bake for 10 minutes, shaking the pan halfway for even heating.

Separate the nuts into two bowls, into one add 100g of pistachios (this will be for the crust) and into the other 127g (this is for the filling and optionally for the whipped cream).

First process the nuts for the crust, blend them on high until you have a pistachio flour, it should look like almond flour, the nuts being in little bits. Transfer back into the bowl and let cool.

Add the nuts for the filling (127g) into the food processor and this time we’re going to process on high until we have a loose paste. This can take up to 30 minutes depending on your food processor and may require scraping the bowl a few times. Once you can stir the paste and it easily runs off the spoon when lifted, it’s done. Set aside to cool.

If making ahead of time, store both the ‘pistachio flour’ and ‘pistachio paste’ in an airtight container. The flour should be kept at room temperature, the paste in the fridge.

Preheat the oven to 350 F. Set a sheet of parchment paper over the bottom of a 8 inch or 9 inch springform pan then clip the ring to it.

Remove the cream from the oreos then weigh them to ensure you have the right amount. Grind them in a food processor until you have fine crumbs.

In a medium sized heatproof bowl, melt the butter. Set the oreo crumbs (or graham cracker crumbs) into the bowl along with the ground pistachios (pistachio flour) and the powdered sugar. Stir until mixed and you have wet crumbs.

Press the crumbs into the bottom and up the sides of the pan, use a measuring cup or jar to help you pack them into an even, tall layer.

Bake the crust for 10 minutes. If it looks warped out of the oven, use the cup to press it back into place. Let cool fully before making the filling.

The cream cheese must be at room temperature before starting. Set it in a medium sized bowl and press it into the bottom of the bowl to remove lumps. Add the pistachio paste to the bowl, the vanilla and salt and use a hand mixer to beat until well mixed - but stop once it is, we don’t want to make the cream cheese runny.

Add the powdered sugar and cold heavy cream to the bowl and beat until the mix is thick, fluffy and holds ‘stiff peaks’ by leaving ribbons in the mix. It should not slop off the spoon when lifted.

Pour the filling into the chilled crust. Smooth into an even layer. Set in the fridge to chill for at least 4 hours but preferably overnight so it can set properly.

Set all the ingredients in a food processor and process until the mix is thick and fluffy, it should not drop off the spoon when lifted. Spread over the chilled pie and sprinkle with additional nuts, if desired.