Preheat oven to 350°F (175°C).
Butter the bottoms and sides of a 9x13 inch baking dish.
Layer 8 sheets of phyllo dough in the dish, brushing each sheet with melted butter.
Sprinkle a thin layer of chopped pistachios over the dough.
Repeat layers (dough, butter, pistachios) until all ingredients are used, ending with about 6-8 layers of dough.
Using a sharp knife, cut the baklava into diamond or square shapes all the way to the bottom of the dish.
Bake for about 45 minutes until baklava is golden and crisp.
While baklava is baking, combine sugar, water, honey, vanilla extract, and cinnamon in a saucepan over medium heat. Bring to a boil, then reduce heat and let simmer for about 20 minutes.
Remove baklava from the oven and immediately pour the syrup over it. Let cool completely before serving.