Preheat the oven to 350°F/180°C/Gas 4 and brush an 11 x 11″ baking dish with melted butter.**
Add one sheet of filo pastry to the baking dish and brush the dough with melted butter. Repeat this process with 10 more sheets of filo, making sure to brush with butter in between.
Place the walnuts into a food processor and pulse until finely chopped. Transfer to a bowl, add the cinnamon and cloves, and stir to combine.
Spread the filling over the pastry layer, then continue to layer with 15 sheets of filo on top, brushing each layer with butter as before.***
Place the dish of baklava in the refrigerator for at least 15 minutes to chill for even slicing.
Remove the baklava from the fridge and use a sharp knife to cut through the baklava into 4 vertical long strips. Then make 5 or 6 diagonal cuts to create the traditional diamond-shaped slices.† Pour any remaining butter over the baklava.
Place the baklava in the preheated oven and bake for 50 – 60 minutes or until the filo sheets are crispy and golden brown.
Meanwhile, make the honey syrup by combining sugar, honey, water, and slices of lemon in a pan over medium heat. Simmer the syrup for 10 minutes, then remove from the heat and stir in the lemon juice.
When the baklava has finished baking, remove it from the oven and while it is still piping hot, pour the syrup all over it. Sprinkle some finely chopped walnuts on top of each diamond for added garnish if desired.
Leave the dish of baklava to cool at room temperature for at least 4 – 6 hours before serving. Enjoy!