Prepare the Crust: In a mixing bowl, combine graham crackers crumbs, ground pistachios, and granulated sugar. Mix well.
Add melted butter to the crumb mixture and stir until everything is well coated with butter.
Press the mixture firmly and evenly into a 9-inch cake pan to form the crust.
Bake the crust at 180°C (350°F) for 5-8 minutes, keeping a close eye on it to avoid burning. Once done, let the crust cool to room temperature.
Lower the oven temperature to 140°C (280°F). In a large bowl, beat room-temperature cream cheese, sugar, sour cream, heavy cream, salt, and vanilla extract with an electric mixer until smooth and creamy.
Add the pistachio paste to the cream cheese mixture and mix until fully combined.
Sift the cornstarch into the mixture and continue mixing until smooth and lump-free.
Whisk the eggs and gently fold them into the batter until everything is creamy and well blended.
Pour the cheesecake batter over the prepared crust. Tap the pan gently on a flat surface to release any air bubbles.
Bake at 140°C (280°F) for about 1 hour, until the edges are set and the center is slightly jiggly.
Let the cheesecake cool in the oven with the door slightly open for 1-2 hours. Afterward, wrap the cheesecake in plastic wrap and refrigerate for at least 5 hours or overnight.
Make the Pistachio Topping:
In a medium bowl, combine chopped white chocolate, pistachio paste, and heavy cream. Microwave in 30-second intervals or use a bain-marie, stirring between intervals, until smooth.
Stir in chopped pistachios.
Carefully remove the cheesecake from the pan by running a knife along the edges. Spread the pistachio topping evenly over the cheesecake with a spoon or spatula.
Slice, serve, and enjoy this creamy pistachio delight!