Preheat oven to 375°F. Slice squash halves into 1/2" half-moon-shaped pieces. Spray a large baking sheet with a light dusting of oil and sprinkle with a little sea salt and pepper. Place the slices on the sheet in a single layer. Lightly spray the tops and sprinkle with salt and pepper. Bake until the slices are tender, about 35 minutes. Remove from oven and set aside to cool; lower oven temperature to 350°F. Empty Alfredo sauce into a sauce pan; warm over very low heat, just enough to liquefy, and remove from heat. Place ricotta, spinach, nutmeg and a pinch of salt into a bowl and combine. Set aside. Assemble lasagna: Coat the bottom of a 9" x 13" baking dish with a light layer of Alfredo sauce. Place four sheets of noodles side by side and top them with more Alfredo sauce. Next, add squash in a single layer. Top squash with more Alfredo sauce and another layer of noodles. Top noodles with all of the ricotta-spinach mixture and smooth out. Top with another layer of noodles, then Alfredo sauce and the last of the squash. Pour over the remainder of Alfredo sauce and top with Mozzarella & Parmesan cheeses. Cover with foil and bake for 40 minutes. Poke to check for noodle tenderness and uncover for 10 minutes or until cheese is golden and bubbly. Remove from oven and rest 15 minutes before slicing.