Smear the tray with the melted fats, put several sheets in it, sprinkle with the walnuts mixture, pour fats on again. Place several more sheets and sprinkle with ground pistachios. Continue until out of sheets. Distribute the cinnamon as desired, be sure to smear with the fats every 3-4 sheets.
Cut the baklava into pieces, pour on the rest of the fats after heating them and bake in a preheated 302°F (150 °C) oven for about 90 min.
While it's baking, make the syrup. Mix the sugar and water and heat them on a moderate stove. Bring to a boil and cook 20 min. until thickened. Remove from the stove, add the juice of 1/2 lemon and 2 packets powdered vanilla.
Let the baklava cool, then pour the syrup (hot or cool) over it. Leave it for 24 hours to syrup well, sprinkle with ground pistachios and serve.
Source: Mariana Hristozova.