Preheat your oven to 350°F (175°C). Grease a 9-inch springform pan. Unroll the phyllo dough, keeping it covered with a damp towel to prevent drying. Take one sheet of phyllo, place it in the pan, and brush lightly with melted butter. Repeat with 8-10 more sheets, layering them and brushing each with butter. Sprinkle about 1/4 cup of the chopped pistachios over these layers. Continue layering 8-10 more phyllo sheets, brushing each with butter.

Carefully trim any excess phyllo hanging over the edge of the pan, or gently fold it in. Bake the phyllo crust for 10-12 minutes, or until it's golden brown and slightly crisp. Remove from oven and reduce oven temperature to 325°F (160°C).

In a large bowl, using an electric mixer, beat the softened cream cheese and granulated sugar together on medium speed until smooth and creamy, about 2-3 minutes. Scrape down the sides of the bowl. Add the eggs one at a time, mixing just until combined after each addition. Stir in the vanilla extract and sour cream until just incorporated. Be careful not to overmix, as this can lead to cracks in the cheesecake.

Pour the cheesecake filling into the par-baked phyllo crust. Bake for 50-60 minutes, or until the edges are set and lightly golden, but the center still has a slight jiggle. Turn off the oven, crack the door open slightly, and let the cheesecake cool in the oven for 1 hour. This helps prevent cracking.

While the cheesecake is cooling, combine the honey, water, and lemon juice in a small saucepan. Bring to a gentle simmer over medium heat, stirring until the honey is fully dissolved. Remove from heat and stir in the orange blossom water, if using. Set aside to cool slightly to a warm temperature.

Once the cheesecake has cooled in the oven, remove it and place it on a wire rack. While still slightly warm, slowly pour the warm honey syrup evenly over the entire top of the cheesecake. Let it cool completely at room temperature, then cover loosely with plastic wrap and refrigerate for at least 4-6 hours, or preferably overnight, to allow it to set fully and absorb the syrup.

Before serving, carefully run a thin knife around the edge of the pan before removing the springform side. Garnish the top with the remaining 3/4 cup of chopped pistachios. Slice and enjoy!