01 - Preheat your oven to 350°F. Generously grease a 9x13-inch baking pan with melted butter, ensuring all corners and sides are coated.
02 - Combine walnuts, almonds, pistachios (if using), sugar, cinnamon, and cloves in a mixing bowl. Stir thoroughly to distribute spices evenly throughout the nuts.
03 - Place one sheet of phyllo dough in the prepared pan. Brush lightly but completely with melted butter. Repeat this process, layering and buttering 6-8 sheets total for the base layer.
04 - Sprinkle one-third of the spiced nut mixture evenly across the phyllo base, ensuring complete coverage to the edges.
05 - Layer and butter 4-5 additional sheets of phyllo dough. Spread another one-third of the nut mixture evenly over the phyllo.
06 - Add another 4-5 buttered phyllo sheets. Distribute the remaining one-third of nut mixture evenly across the surface.
07 - Layer remaining phyllo sheets, brushing each generously with melted butter, including the very top sheet. Ensure the top layer is well buttered for optimal crispness.
08 - Using a sharp knife, carefully cut the layered pastry into diamond or square shapes. Cut completely through all layers to allow syrup penetration.
09 - Bake for 35-40 minutes until the baklava achieves a rich golden brown color and crisp texture throughout.
10 - While baklava bakes, combine sugar, water, and lemon juice in a medium saucepan. Bring to a boil and cook for 8-10 minutes until sugar dissolves completely. Remove from heat and stir in honey and rose water or orange blossom water if using.
11 - Immediately pour the hot syrup evenly over the hot baked baklava. Allow to cool completely at room temperature, letting the syrup absorb fully into the layers before serving.