Build your lasagna in this order: Béchamel, noodles, apples, noodles, spinach ricotta, noodles, béchamel, apples, noodles, béchamel, apples, noodles, béchamel, mozzarella
Bake the lasagna for 20 minutes covered and for an additional 20 minutes uncovered. When the cheese is golden and bubbly, take the lasagna out of the oven.