Set aside the walnuts, cinnamon, and sugar in a small bowl.
With melted butter, grease the 13” by 9” pan.
Unravel the phyllo dough into sheets and put one sheet into the pan. Brush this sheet with butter and add a second sheet on top. Brush that sheet with butter. Turn the long edges over to fit the pan.
Sprinkle ¼ of the nut mixture over the phyllo dough sheet and place another two phyllo dough sheets over that. Butter those.
Repeat step four 18 times. Place any extra dough sheets on top, brushing them with butter as well.
Slice the phyllo sheet dish into 2” diamonds.
Place the baking pan into the oven and bake for 50 minutes at 350 degrees or until the dough has turned golden brown.
In a saucepan, place the syrup ingredients and mix them until fully combined. Bring it to a boil. Once boiled pour the syrup over the baklava.
Let the entire dish with the syrup cool and then serve.