Preheat the oven to 350 degrees F. Line a 9 inch spring form pan with parchment paper.
In a medium bowl, combine the pistachios, almonds, chocolate chips, and cinnamon.
Fold 1 sheet of phyllo dough in half and then place in the prepared pan. Brush the phyllo dough with melted butter. Repeat, layering 8 more times, placing the sheets of dough over top of each other.
Spoon half of the nut/chocolate mix over the dough. Now add another 8 sheets of phyllo, brushing each with butter. Spoon over the remaining filling. Add another 8 sheets of phyllo, again brushing each with butter.
Cut the baklava into 8 triangles. Place the pan on a baking sheet and transfer to the oven and bake for 45-50 minutes, until phyllo is golden brown.
Meanwhile, combine ½ cup water and the honey in a medium saucepan and bring to a boil. Reduce the heat and simmer 5 minutes until thickened slightly. Remove from the heat and stir in the vanilla.
Pour the syrup over the warm baklava and let soak for 2 hours or overnight.
