Prepare Pie Crust:

1. In a food processor, combine the vanilla wafers, pistachios, and sugar. Process until the mixture resembles sand. Transfer the crumb mixture to a bowl, add the melted butter, and mix to combine. The mixture should be damp, like wet sand, and will hold together when squeezed. If it is too dry, add more melted butter, a tablespoon at a time. If it’s too wet, add a tablespoon more vanilla wafer crumbs until it’s the correct consistency.
2. Pour the crumbs into a 9-inch pie plate and start pressing them up the sides of the pie plate to form the edges first. Once the edges are formed, work the crumbs down to evenly distribute them into the bottom of the pie plate. Then, pack them down into an even layer using a flat-bottomed cup or measuring cup.
3. Place the pie crust in the freezer while preparing the filling.

Make the Filling:

1. With a hand mixer or a stand mixer fitted with a whisk attachment, whip the cream until stiff peaks form. Set aside in a separate bowl.
2. To the now-empty bowl, add the mascarpone, powdered sugar, and orange zest. Switch to the paddle attachment if using a stand mixer. Beat on medium speed until completely smooth, about 2 minutes. Scrape down the sides of the bowl with a rubber spatula and add the ricotta cheese. Beat on low speed until well combined, about 1 minute.
3. Add ⅓ of the whipped cream to the cream cheese mixture and fold it in with a rubber spatula by hand until it is completely combined.
4. Add the remaining whipped cream to the bowl and gently fold it in, being careful not to deflate the whipped cream.
5. Transfer the filling to the prepared pie crust and smooth over the top. Place the pie in the refrigerator to set up. It needs at least 4 hours of chilling time, but preferably at least 12 hours or overnight.
6. Right before serving, garnish with chocolate chips and powdered sugar.