01 - Preheat oven to 350°F. Grease a 9x13-inch baking pan with melted butter.
02 - In a bowl, mix walnuts, almonds, pistachios (if using), sugar, cinnamon, and cloves for the nut filling.
03 - Place one sheet of phyllo in the pan. Brush lightly with melted butter. Repeat, layering and buttering 6-8 sheets.
04 - Sprinkle 1/3 of the nut mixture evenly over the phyllo.
05 - Layer and butter 4-5 more sheets of phyllo. Add another 1/3 of the nut mixture.
06 - Repeat with another 4-5 sheets, then the last 1/3 of the nut mixture.
07 - Finish with the remaining phyllo sheets, buttering each, including the top layer.
08 - Using a sharp knife, cut baklava into diamonds or squares.
09 - Bake 35-40 minutes until golden and crisp.
10 - Combine sugar, water, and lemon juice in a saucepan. Boil 8-10 minutes. Remove from heat, stir in honey and rose/orange blossom water (if using).
11 - Pour hot syrup evenly over hot baklava. Let cool completely to absorb syrup before serving.