Preheat oven to 400°F. Grease a 13” x 9” baking dish with nonstick cooking spray.
Heat ½ tablespoon olive oil in a skillet on a medium setting. Add the spinach, salt and pepper. Cook until wilted, about 5-6 minutes. Remove spinach and place in a bowl to cool.
Once the spinach has cooled, add ricotta, egg, garlic powder, salt and pepper to the bowl. Mix to combine. Set aside.
In a large bowl, mix together the pumpkin, peppers, milk, cinnamon, nutmeg, ginger, allspice, salt and pepper.
To create the lasagna, begin layering in the greased baking dish. Spread 1 cup (heaping) of pumpkin mixture along the bottom of the dish. Next, sprinkle with ½ cup Parmesan. Arrange 5 lasagna noodles on top: 4 vertically and 1 horizontally. Spread half of the spinach-ricotta cheese mixture on top of the noodles. Top with ¾ cup of the shredded mozzarella.
Repeat layering with 1 cup (heaping) of the pumpkin mixture. Sprinkle with ½ cup of Parmesan. Continue with remaining noodles, spinach-ricotta mixture and ¾ cup shredded mozzarella. Top with any remaining pumpkin and ½ cup of Parmesan. Finish with 1 ½ cups shredded mozzarella cheese.
Cover with foil. Bake for 25 minutes. Remove the foil and bake for another 15-20 minutes, or until the cheese bubbles and begins to brown.