01 - Preheat oven to 350°F. Thoroughly grease a 9x13-inch baking pan with melted butter.
02 - Combine walnuts, almonds, pistachios (if using), sugar, cinnamon, and cloves in a mixing bowl. Toss until evenly distributed.
03 - Place one phyllo sheet in the prepared pan. Brush lightly with melted butter. Repeat layering and buttering 6-8 sheets total for the bottom layer.
04 - Sprinkle one-third of the nut mixture evenly across the buttered phyllo sheets.
05 - Layer and butter 4-5 additional phyllo sheets. Spread another one-third of the nut mixture over the dough.
06 - Add another 4-5 buttered phyllo sheets, followed by the remaining one-third of the nut mixture.
07 - Layer remaining phyllo sheets, buttering each thoroughly including the topmost sheet.
08 - Using a sharp knife, cut completely through the layered phyllo to create diamond or square shapes.
09 - Bake for 35-40 minutes until pastry turns golden brown and achieves crisp texture throughout.
10 - While baklava bakes, combine sugar, water, and lemon juice in a medium saucepan. Boil for 8-10 minutes until sugar dissolves completely. Remove from heat and stir in honey plus rose or orange blossom water if using.
11 - Immediately after removing baklava from oven, pour hot syrup evenly over the hot pastry. Allow to cool completely at room temperature so syrup absorbs fully before serving.