Preheat oven to 400° F and grease a 9x13 baking dish.
Spread approximately 1 cup of Alfredo sauce onto the bottom of the pan.
Place ravioli in the sauce making a single layer that covers the bottom of the dish.
Layer half of the chopped spinach over the ravioli.
Layer 8 ounces of shredded chicken on top of the spinach.
Spoon approximately 1.5 cups of Alfredo sauce evenly over the chicken.
Top with 4 ounces of mozzarella cheese.
Repeat the layers, ravioli, spinach, chicken, sauce, cheese.
Cover with foil and bake for 30 minutes. After 30 minutes remove the foil and continue baking for an additional 15 minutes, or until the cheese begins to brown.
Remove from the oven and let stand for 10 minutes before serving.