3 cups walnuts, divided
1 cup blanched almonds
1 teaspoon cinnamon
1/2 teaspoon ground cloves
12 sheets phyllo dough
1/4 cup light safflower oil
1 1/4 cups date sugar
2 tablespoons lemon zest
2 tablespoons maple syrup
1 teaspoon vanilla
1/2 teaspoon almond extract
Lightly grease a 9x13-inch pan and set aside. Coarsely chop half of the walnuts and place them in a bowl. Finely chop the remaining half of walnuts and the almonds. Add the finely chopped nuts to the bowl along with the cinnamon and cloves, stir well to combine, and set aside.
Place the stacked sheets of phyllo dough flat on a cutting board, cut them in half lengthwise, stack the cut sheets on top of each other, remove 6 sheets from the stack, and cover the remaining with a towel to keep them from drying out.
Place 1 sheet of phyllo dough in the bottom of the greased pan and lightly brush it with a little of the oil. Repeat the layering and oiling procedure for the remaining 5 sheets of phyllo dough. Sprinkle one third of the reserved nut mixture evenly over the top of the stacked phyllo dough. Repeat the layering and oiling procedure with 6 additional sheets of phyllo dough, sprinkle with another third of the nut mixture, and repeat this procedure ending with a phyllo layer.
Using a sharp knife, carefully make 4 evenly-spaced vertical cuts through the entire stack of phyllo, make 5 evenly-spaced lengthwise cuts, and then cut each piece in half diagonally.
Bake at 350 degrees for 20 minutes, lower the heat to 300 degrees, and bake an additional 25 to 30 minutes or until evenly golden brown on top.
Meanwhile, in a saucepan, combine the date sugar, lemon juice, lemon zest, and maple syrup, and cook over medium heat until thickened. Remove from heat and stir in the vanilla and almond extract. Pour the syrup mixture over the baklava as soon as it comes out of the oven.
Let baklava cool before serving. Store in an airtight container in the refrigerator for up to one week or extras can be frozen.