To make the syrup, combine the sugar and water in a small saucepan over medium heat. Stir until the sugar dissolves. When the mixture comes to a boil, add the lemon juice and let it simmer for 10 minutes until it thickens. Add the rose water and orange blossom water, remove from heat, and pour the syrup into a large bowl to cool.

To prepare the baklava, brush a baking pan the same size as the phyllo sheets with butter. Lay 12 sheets of phyllo dough in the pan, brushing each sheet well with butter.

Spread the ground walnuts evenly over the 12 sheets, then cover with the remaining 12 sheets, brushing each with butter as well.

Cut the dough into diamond shapes, making sure to cut through all the layers.

Bake in a preheated oven at 350°F (180°C) for 30 minutes, or until the pastry is puffed and golden brown.

Remove the pan from the oven and pour the syrup over the baklava. Let it sit until all the syrup is absorbed.

Serve in pieces.