Preheat the oven to 350°F (175°C). Spread the kataifi on a 10x15-inch rimmed baking sheet and toast for 10 to 12 minutes, stirring halfway, until golden. Let cool for 15 minutes.

In a bowl, mix 3/4 cup of toasted kataifi, graham cracker crumbs, chopped pistachios, melted butter, and sugar. Press into the bottom of a 9-inch springform pan. Bake for 12 to 15 minutes until golden, then reduce oven temperature to 325°F (163°C).

Whisk together 1 cup of whipping cream, 1 cup of pistachio cream, and tahini until smooth.

In a small bowl, combine white chocolate chips and remaining 1/3 cup of whipping cream; microwave until melted (1 to 2 minutes) and let cool slightly.

Beat cream cheese and 1/4 cup sugar together with an electric mixer until smooth. Add eggs one at a time and beat after each addition, then mix in white chocolate mixture and vanilla extract.

Pour half of the cream cheese mixture into the crust, then top with the pistachio cream mixture, and finally pour the rest of the cream cheese mixture on top. Use a spatula or toothpick to swirl gently.

Bake for 55 to 60 minutes until edges are set. Turn off the oven, leave the door ajar, and let cheesecake cool to room temperature for about an hour. Cover and refrigerate overnight.

Combine remaining pistachio cream, tahini, and kataifi. Spread over the cooled cheesecake. Melt milk chocolate and remaining whipping cream in the microwave (1 to 2 minutes) and pour over cheesecake, spreading evenly.

Chill in the pan for at least an hour or up to four days before serving. Garnish with extra pistachios, slice, and serve.