How to Make It
Preheat oven to 400°F. Toss together butternut squash, 2 teaspoons of the oil, 1/2 teaspoon of the salt and 1/4 teaspoon of the pepper. Arrange in a single layer on a rimmed baking sheet; bake in preheated oven until softened and lightly browned, 15 to 20 minutes. Set aside.
While squash cooks, heat remaining 2 teaspoons oil in a large skillet over medium-high. Add onion and 1/4 teaspoon of the salt, and cook, stirring often, until softened and translucent, 3 to 4 minutes. Add spinach, and cook, stirring often, until wilted, 1 to 2 minutes. Remove from heat, and set aside.
Combine shredded provolone and mozzarella in a medium bowl. Stir together ricotta, parsley, eggs, 1 1/2 cups of the shredded cheese mixture, and remaining 3/4 teaspoon salt and 1/2 teaspoon pepper in a large bowl.
Spread 1 cup of the marinara on bottom of a 13- x 9-inch baking dish lightly coated with cooking spray. Arrange 4 noodles side by side over sauce; spread half of ricotta mixture over noodles. Spread roasted squash evenly over ricotta mixture; top with 1 1/2 cups of the marinara. Top with 4 more noodles and remaining ricotta mixture. Spread spinach mixture evenly over ricotta mixture; top with 1 1/2 cups of the marinara. Top with remaining 4 noodles, 1 cup marinara. Sprinkle with Parmesan and remaining shredded cheese mixture. Cover with aluminum foil, and bake at 400°F for 35 minutes. Uncover and bake an additional 20 minutes or until golden and bubbly. Let stand 10 minutes before cutting into 10 slices.