Spinach and Pesto Lasagna

From Epicurious.

3 cups ricotta cheese
1 cup shredded Parmesan cheese
1 large egg
2 10-ounce packages frozen chopped spinach, thawed, squeezed dry
1 7-ounce jar prepared pesto
4 cups bottled chunky pasta sauce
12 lasagna noodles
2 cups grated mozzarella cheese

Blend ricotta and Parmesan in medium bowl.
Season cheeses with salt and pepper; stir in egg.
Blend spinach and pesto in another medium bowl.
Brush 13x9x2-inch glass baking dish with oil.
Spread 1 cup pasta sauce in prepared dish.
Arrange 3 noodles side by side atop sauce.
Spread 1 1/4 cups ricotta cheese mixture over in thin layer.
Drop 1/3 of spinach mixture over by spoonfuls.
Repeat layering with sauce, noodles, ricotta cheese mixture and spinach mixture 2 more times.
Top with remaining 3 noodles and 1 cup sauce.
Let sit overnight.
Preheat oven to 350°F.
Cover lasagna with foil. Bake 35 minutes.
Uncover; sprinkle with cheese.
Bake lasagna until heated through, sauce bubbles and cheese on top is melted, about 15 minutes longer.
Let stand 10 minutes.