Almond Pistachio Baklava

3 cups sugar, divided
1-1/2 cups water
1/2 cup honey
5 teaspoons lemon juice
3 cups unsalted pistachios
2-1/4 cups unsalted unblanched almonds
1-1/2 teaspoons ground cinnamon
1/2 teaspoon ground nutmeg
1-1/2 cups butter, melted
2 packages (16 ounces each, 14x9-inch sheet size) frozen phyllo dough, thawed.

Directions:

1. In a small saucepan, bring 2 cups sugar, water, honey and lemon juice to a boil. Reduce heat; simmer 5 minutes. Cool.
2. Preheat oven to 350°. Working in batches, combine pistachios and almonds in a food processor; cover and process until finely chopped. Transfer to a large bowl. Stir in cinnamon, nutmeg and remaining sugar; set aside. Brush a 15x10x1-in. baking pan with some of the butter. Unroll one package of phyllo dough; cut stack into a 10-1/2x9-in. rectangle. Repeat with remaining phyllo. Discard scraps.
3. Line bottom of prepared pan with two sheets of phyllo dough (sheets will overlap slightly). Brush with butter. Repeat layers 9 times. (Keep dough covered with a damp towel until ready to use to prevent it from drying out.) Sprinkle with a third of the nut mixture.
4. Top with 10 layers of buttered phyllo dough and a third of the nut mixture; repeat layers. Top with remaining phyllo dough, buttering each layer.
5. Using a sharp knife, cut into 1-1/2-in. diamond shapes. Bake until golden brown, 40-45 minutes. Place pan on a wire rack. Slowly pour cooled sugar syrup over baklava. Cover and let stand overnight.