Preheat your oven to 325°F (160°C). Grease a 9-inch springform pan to prepare for baking.

In a bowl, mix graham cracker crumbs, melted butter, and optional sugar until it feels like wet sand. Press this mixture into the bottom of your pan. Bake for 8-10 minutes, then let it cool.

In a large bowl, beat the cream cheese and sugar until smooth. Add the eggs one at a time, mixing well after each addition. Next, add the vanilla extract, sour cream, and heavy cream. Mix until everything is smooth, then pour it over the cooled crust.

In another bowl, mix chopped pistachios, nuts (if using), sugar, cinnamon, and honey.

Take a sheet of phyllo dough and brush it with melted butter. Lay it over the cheesecake mixture. Repeat with 8-10 sheets of phyllo, buttering each layer. Spread the baklava mixture over the phyllo layers.

Cover the pan loosely with foil and bake in the oven for about 1 hour or until the center is just set. Let it cool completely in the oven with the door slightly open. Chill in the refrigerator for at least 4 hours, or overnight for best results.

For the syrup, combine honey, water, sugar, lemon juice, and vanilla extract in a small saucepan. Bring it to a boil and then simmer for about 10 minutes. Let it cool slightly.

Pour the cooled syrup over the cheesecake, and garnish with extra chopped pistachios before serving.