Preheat the oven to 350F

Start by making the simple syrup by putting the sugar and the water in a pot and bringing to a boil. Once it boils, lower to a simmer for 7 minutes. Allow to cool

To prepare the filling, grind the walnuts in a food processor until you achieve a coarse consistency (as pictured). Each walnut should break up to about a fifth of its size

Mix the walnuts with the ground cardamom and also add 3/4 cups simple syrup (leave the rest for later). Mix until it looks well combined and wet

Unwrap the first filo pastry box (it dries out so work fast). Measure the dimensions against your pan (I used a 13 inch by 18 inch pan) and snip any excess using scissors. The filo sheets should sit inside the pan up to the edges

Start the layering process by brushing the bottom of the pan generously with the butter/oil. Then layer 3 sheets of filo on top, ensuring you press down and remove air bubbles as best as you can every time you add a sheet

Brush the third layer of filo generously with the butter/oil, then continue layering, brushing every third layer. If you are using 10 or 11 sheets, also brush the top most layer with butter/oil (even if it is not the third sheet). If you have more sheets, feel free to use up to 15 layers

Spoon the walnut mixture onto the filo pastry covering it all evenly and pack it down using the back of a spoon or your hand

Unwrap the second box of filo pastry and measure it the same way. Then start layering the filo sheets and brush every third sheet generously with butter/oil, making sure you remove air bubbles. Continue until you reach the top, and also brush the top generously with butter/oil

Using a sharp knife, make straight cuts parallel to the long edge of the pan, roughly 1 inch in size. Hold down the pastry gently as you cut, and use a rocking motion so the pastry does not drag out of place. You should be able to fit 8-10 rows if using the same size pan. You can also cut them bigger for an easier option

Then make diagonal cuts running from one corner of the pan all the way to the opposite corner to create diamond shapes (refer to video). Go over all the cuts twice to ensure you cut all the layers

Bake for 45-50 minutes until the Baklawa is a light golden colour

Take it out of the oven and pour the remaining cooled simple syrup on top. You may hear a splashing sound and that's okay!

Optional: garnish with crushed pistachios and rose petals

Allow the Baklawa to cool completely before serving. Also read the storing instructions above