Make the syrup by heating sugar, water, lemon juice, and rose water. Bring to a boil, then simmer 5 minutes. Let it cool fully.
Pulse pistachios until small pieces form. Mix with sugar and rose water.
Brush a thin layer of melted butter on the bottom of your baking pan.
Add 8–10 filo sheets, brushing each lightly with butter.
Spread a thin, even layer of pistachio filling and press gently.
Add another 8–10 butter-brushed filo sheets on top.
Cut the baklava into diamonds or squares before baking.
Bake at 350°F (175°C) for 35–45 minutes until crisp and golden.
Pour the cooled syrup over the hot baklava and let it soak.
Cool fully before serving to allow the layers to set.