01 - Preheat your oven to 350°F. Generously grease a 9x13-inch baking pan with melted butter, ensuring complete coverage.
02 - In a large mixing bowl, combine finely chopped walnuts, almonds, pistachios (if using), sugar, cinnamon, and cloves. Mix thoroughly until spices are evenly distributed throughout the nuts.
03 - Place one sheet of phyllo dough in the prepared pan. Brush lightly but evenly with melted butter. Repeat this process, layering and buttering 6-8 sheets total to create a sturdy base.
04 - Sprinkle one-third of the prepared nut mixture evenly over the buttered phyllo sheets, ensuring complete coverage from edge to edge.
05 - Layer and butter 4-5 additional sheets of phyllo dough. Add another one-third of the nut mixture, spreading evenly.
06 - Repeat with 4-5 more buttered phyllo sheets, followed by the remaining one-third of the nut mixture.
07 - Finish with all remaining phyllo sheets, buttering each sheet thoroughly including the very top layer. Press gently to compact the layers.
08 - Using a sharp knife, carefully cut the unbaked baklava into diamond or square shapes. Cut completely through all layers to prevent tearing after baking.
09 - Bake for 35-40 minutes until the phyllo becomes deeply golden brown and crisp throughout. Rotate the pan halfway through for even browning.
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 slightly thickened. Remove from heat, stir in honey and rose water or orange blossom water if using.
11 - Immediately pour the hot syrup evenly over the hot baklava as soon as it exits the oven. Allow to cool completely at room temperature for several hours or overnight to ensure full syrup absorption before serving.