Preheat the oven to 350°F (175C/155C Fan). Mix together the ground almonds and ground cinnamon, set aside.
Carefully unroll the filo pastry and cut the sheets in thirds (lengthwise) to fit the size of your baking tray. See the photos above for example. Place a damp cloth over the filo to keep this from drying out while you work.
Brush melted butter in the base of the baking dish and place your first sheet of filo. Brush this again with butter and layer another sheet. Continue repeating until you have a layer of 7 sheets (or a third of your filo).
Brush the top sheet with butter and sprinkle ⅓ of the almond cinnamon mixture over this and spread evenly.
Place another sheet of filo, and butter the top of this. Repeat layering the filo until you have 3 or 4 sheets. Then add another third of the almond mixture, spreading evenly. Layer three or 4 more sheets of filo, buttering each sheet. Add your final third of the almond mixture and then layer the remaining 6 or 7 sheets of filo, buttering each sheet.
Brush the top with butter and then slice in a diamond pattern - see the photos above for example.
Place in the oven and bake for 45-50 minutes, meanwhile make the syrup.
For the syrup, place the sugar, water and cinnamon sticks in a saucepan. Bring this to a boil over a medium heat and stir until the sugar has dissolved. Add the honey, orange blossom water and vanilla. Continue to simmer for about 20-30 minutes.
As soon as the pastry comes out of the oven, pour the syrup over this and leave to cool for at least an hour.
Use a spatula to remove slices from the tray and serve.