01 - Preheat your oven to 350°F. Grease a 9x13-inch baking pan thoroughly with melted butter.
02 - Combine walnuts, almonds, pistachios (if using), sugar, cinnamon, and cloves in a mixing bowl. Mix until evenly distributed.
03 - Place one sheet of phyllo dough in the prepared pan. Brush lightly with melted butter. Repeat, layering and buttering 6-8 sheets total.
04 - Sprinkle one-third of the nut mixture evenly over the buttered phyllo sheets.
05 - Layer and butter 4-5 additional sheets of phyllo. Distribute another one-third of the nut mixture over the surface.
06 - Add another 4-5 buttered phyllo sheets, then spread the remaining one-third of nut mixture evenly.
07 - Layer remaining phyllo sheets, brushing each with melted butter including the top surface.
08 - Using a sharp knife, cut baklava into diamond or square shapes through all layers.
09 - Bake for 35-40 minutes until phyllo turns golden brown and crisp.
10 - While baklava bakes, combine sugar, water, and lemon juice in a medium saucepan. Boil for 8-10 minutes. Remove from heat, stir in honey and rose water or orange blossom water if using.
11 - Immediately pour hot syrup evenly over hot baklava after removing from oven. Allow to cool completely for syrup absorption before serving.