Make the syrup: combine Granulated Sugar, Water and Lemon Juice in a small saucepan; bring to a gentle boil, then reduce heat and simmer 8–10 minutes until slightly thickened. Remove from heat and let cool to room temperature.
Preheat the oven to 180°C (350°F) and grease a 9-inch (23 cm) round baking pan with a little Ghee.
Prepare the Kunafa Dough by loosening and shredding it with your fingers; toss the shredded pastry with most of the melted Ghee so it is evenly coated and slightly separated.
Press about half of the buttered kunafa into the bottom of the prepared pan, pressing firmly to form an even layer.
Make the filling by roughly chopping the Mixed Nuts and tossing them with a pinch of Granulated Sugar and Ground Cinnamon so the spices and sugar are evenly distributed.
Spread the nut mixture evenly over the bottom pastry layer, then top with the remaining kunafa, pressing gently to compact into a uniform layer.
Bake for 25–30 minutes, or until the top is deeply golden and crisp.
As soon as the kunafa comes out of the oven, slowly pour the cooled syrup over the hot pastry so it soaks in evenly; allow the pastry to absorb the syrup for 5–10 minutes.
Garnish with chopped Pistachios before slicing, let rest a few minutes, then serve warm so the filling remains soft and the exterior stays crisp.
