Prepare the syrup by boiling the honey with the water then add the lemon juice and cook for a minute. Set aside to cool.
In a bowl, mix the walnuts and cinnamon.
Cut the baklava dough to the size of your oven dish.
Butter your oven dish and place one sheet of baklava dough over, then brush it with butter. Cover with another sheet of baklava dough and continue the same process until you have lined 6 sheets on top of each other.
Sprinkle half the walnut mixture over then repeat the same process with 4 sheets of baklava dough and sprinkle the remaining walnut mixture on top. Then finally repeat the same process with the remaining 4 sheets of baklava dough and brush the top with butter.
Cut the baklava into lozenges and bake in a preheated oven at 175°C for 50 minutes.
Pour the syrup over the baklava as soon as it comes out of the oven.