Transfer the nuts, cardamom, cloves, and cinnamon to a bowl. Mix well to combine.
Brush your pan lightly with olive oil and preheat oven to 350°F (175°C)
Roll into a cigar and cut it in half. Place fingers inside the pan, brush their surface with some more olive oil and repeat with the rest of the phyllo.
Make the syrup: Combine all of the ingredients in a pot and bring to a boil. Boil for 5 minutes.
Remove the baklava from the oven and pour the hot syrup over it. Let it rest for 2-3 hours to absorb all of the syrup.
You can easily halve the recipe and use the rest of the phyllo in another recipe like a savory pie or tart.
Keeps well for up to 4-5 days at room temperature and more than 10 days in the fridge.
If you choose to use lemon slices in the syrup, they may cause it to have a slightly tangy aftertaste. Some people like this, but others don't.