01 - Preheat oven to 350°F. Generously grease a 9x13 inch baking dish with melted butter.
02 - Combine walnuts, pistachios, almonds, sugar, and cinnamon in a bowl. Mix thoroughly to distribute spices evenly.
03 - Unroll phyllo dough and cover immediately with a damp kitchen towel to prevent drying out while working.
04 - Place 8 sheets of phyllo in the prepared dish, brushing each sheet generously with melted butter before adding the next.
05 - Sprinkle approximately one-third of the nut mixture evenly over the buttered phyllo sheets.
06 - Layer 4 more phyllo sheets, buttering each one. Spread half of the remaining nuts over the top.
07 - Place 4 additional phyllo sheets, buttering each. Sprinkle the remaining nut mixture evenly across the surface.
08 - Finish with remaining phyllo sheets, brushing each layer thoroughly with melted butter as you work.
09 - Use a sharp knife to cut the layered pastry into diamond or square shapes before baking. Cut completely through all layers.
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 and peel; let syrup cool slightly.
12 - Immediately upon removing baklava from oven, slowly pour the warm syrup evenly over the entire surface. Allow to cool completely so pastry absorbs syrup fully before serving.