For filling, in a large mixing bowl stir together chopped walnuts, 1/2 cup sugar, and the ground cinnamon. Set aside.
Brush the bottom of a 15x10x1-inch baking pan with some of the melted butter. Unfold phyllo dough. Keep phyllo covered, removing sheets as you need them. Layer one-fourth of the phyllo sheets in the pan, generously brushing each sheet with melted butter as you layer, and allowing phyllo to extend up the sides of the pan. Sprinkle about 1-1/2 cups of filling on top of the phyllo. Repeat layering the phyllo sheets and filling twice.
Layer remaining phyllo sheets atop the third layer of filling, continuing to brush each sheet with butter before adding the next phyllo sheet. Drizzle any remaining butter over the top layers. Trim edges of phyllo to fit the pan. Using a sharp knife, cut through all layers to make 60 diamond-, triangle-, or square-shaped pieces.
Bake in a 325 degree F oven for 45 to 50 minutes or until golden. Slightly cool in pan on a wire rack.
Meanwhile, for syrup, in a medium saucepan stir together the 1-1/2 cups sugar, the water, honey, lemon peel, lemon juice, and stick cinnamon. Bring mixture to boiling. Reduce heat. Simmer, uncovered, for 20 minutes. Remove the stick cinnamon. Pour the syrup over the warm baklava in the pan. Cool completely. Place in an airtight container and store at room temperature for up to 3 days or freeze up to 1 month. Thaw at room temperature for 30 minutes before serving. Makes about 60 baklava.