Baklava has so old history. Although the history of baklava is not well documented, its current form was probably developed in the imperial kitchens of the Topkapı Palace in Istanbul. The Sultan presented trays of baklava to the Janissaries every 15th of the month of Ramadan in a ceremonial procession called the Baklava Alayı.
Baklava is normally prepared in large pans. Many layers of filo dough, separated with melted butter and vegetable oil, are laid in the pan. A layer of chopped nut typically walnuts or pistachios, but hazelnuts are also sometimes used—is placed on top, then more layers of filo. Most recipes have multiple layers of filo and nuts, though some have only top and bottom pastry.
Baklava is usually served at room temperature, often garnished with ground nuts.