Preheat the oven to 325°F (165°C) and grease a 9-inch springform pan.

In a medium bowl, combine graham cracker crumbs, melted butter, and brown sugar until blended. Press the mixture into the bottom of the pan to form an even crust. Bake for about 8-10 minutes and set aside to cool.

In a bowl, mix together chopped pistachios, walnuts, sugar, cinnamon, melted butter, and honey. Spread this mixture evenly over the cooled crust.

In a large bowl, beat cream cheese and sugar until smooth. Incorporate eggs one at a time, mixing well after each addition. Stir in Greek yogurt, lemon juice, cornstarch, and vanilla extract until fully blended.

Pour the cheesecake filling over the baklava layer in the pan.

Place the cheesecake in the oven and bake for 50-55 minutes, or until the center is set but still slightly jiggly. Turn off the oven and let the cheesecake cool inside for about 1 hour.

While the cheesecake cools, brush phyllo sheets with melted butter, layer them on top of the cheesecake, and bake for an additional 5-7 minutes until golden and crispy.

In a saucepan, combine honey, water, sugar, lemon juice, and cinnamon. Heat until simmering, stirring occasionally. Let it simmer for 5-7 minutes until slightly thickened.

Drizzle the warm syrup over the cheesecake and refrigerate for at least 4 hours or overnight.

Before serving, sprinkle with chopped pistachios and add a dollop of whipped cream or Greek yogurt.