Preheat oven to 400 degrees F. Line a large baking sheet with parchment paper.

Place the butternut squash on the baking sheet and drizzle with olive oil. Toss until well coated. Season with salt and pepper. Roast for 25 to 30 minutes or until squash cubes are tender. Remove from the oven and let cool for 5 minutes.

While the squash is roasting, cook the lasagna noodles. Bring a large pot of salted water to a boil. Add the dry lasagna noodles and cook to al dente, per package directions. Stir often to prevent from sticking. When done cooking, drain in a colander and rinse with cool water, gently separating any noodles that may be sticking together.

Spread a little olive oil on a large baking sheet. Lay the noodles in an even layer on the sheet, turning them over so that each side gets coated with a little of the olive oil. This will prevent them from sticking together. Set aside.

Make the spinach ricotta mixture. In a large skillet, heat butter over medium heat. Add the shallot and cook for 2 to 3 minutes. Add spinach cook until wilted. Add the garlic and cook for one minute.

In a large bowl, combine the spinach mixture, ricotta cheese, parmesan cheese, egg, sage, thyme, crushed red pepper flakes, salt and pepper. Set aside.

Place the roasted butternut squash in a food processor. Add 1/2 cup vegetable broth, maple syrup, and nutmeg. Process until smooth, the mixture will be thick. Set aside.

To make the bechamel sauce, place the butter in a large saucepan and melt over medium heat. Add the flour and whisk for one minute. Whisk in the milk and bring to a gentle boil, then reduce to a low simmer until the sauce thickens slightly about 3 to 5 minutes. Remove from the heat and season with salt and pepper. Set aside.

To assemble the lasagna, grease a 9x13-inch baking dish. Spread 2/3 cup of the bechamel sauce in the bottom of the dish. Arrange a layer of lasagna noodles (3 noodles) on top of the sauce. Spread 1/3 of the squash puree over the noodles then 1/3 of the spinach ricotta mixture. Top with 1/2 cup of mozzarella cheese and pour 2/3 cup of the bechamel sauce over the noodles. Repeat layering two more times. Top with remaining 3 noodles and remaining 1 1/2 cups mozzarella cheese and 1/4 cup Parmesan cheese. Garnish with sage leaves, if desired. Spray a piece of aluminum foil with cooking spray and tightly cover the baking dish.

Bake for 40 minutes. Remove the foil and bake uncovered for 15 minutes or until the top is golden. Remove from the oven and let the lasagna stand for 10 to 15 minutes before serving.