01 - Preheat oven to 350°F. Generously grease a 9x13 inch baking dish with melted butter.
02 - Combine chopped walnuts, pistachios, almonds, sugar, and cinnamon in a mixing bowl. Toss thoroughly to distribute spices evenly.
03 - Unroll phyllo dough and cover completely with a damp kitchen towel to prevent drying out during assembly.
04 - Place 8 sheets of phyllo in the prepared dish, brushing each sheet generously with melted butter before adding the next sheet.
05 - Sprinkle approximately one-third of the nut mixture evenly across the phyllo base.
06 - Layer 4 additional phyllo sheets, brushing each with butter. Spread half of the remaining nut mixture over this layer.
07 - Add 4 more phyllo sheets, buttering each one. Sprinkle the remaining nut mixture evenly across the surface.
08 - Finish with remaining phyllo sheets, brushing each layer with butter as you stack them.
09 - Using a sharp knife, cut the pastry completely through into diamond or square shapes before baking.
10 - Bake for 35-40 minutes until phyllo turns deep golden brown and becomes crisp throughout.
11 - While baklava bakes, combine water, sugar, lemon juice, honey, cinnamon stick, and orange peel in a saucepan. Bring to boil, then reduce heat and simmer 10 minutes. Remove cinnamon stick and orange peel. Cool slightly.
12 - Immediately pour warm syrup slowly over entire surface of hot baklava as it comes out of oven. Allow to cool completely at room temperature so pastry absorbs syrup fully before serving.