Preheat oven to 350°. Fold two sheets of phyllo at a time, accordion-style; place into a 13x9-in. baking pan. Repeat until all phyllo dough is used, gently fanning out the dough until the pan is filled. Bake phyllo 10 minutes. Remove; sprinkle chopped pistachios within the folds of the phyllo dough. Drizzle melted butter evenly on top. Bake an additional 10 minutes.
Meanwhile, in a medium bowl, whisk together milk, eggs, sugar, vanilla, cardamom and salt until combined. Pour the custard mixture over the phyllo. Bake until the phyllo is browned and crisp, about 25-30 minutes.
In a microwave-safe bowl, combine water, sugar, lemon juice, cinnamon and saffron. Microwave until mixture just begins to boil, about 3-4 minutes. Stir in rose water. Drizzle simple syrup over warm cake. Let cool at room temperature before serving. Store in the refrigerator.
