In a large saucepan over medium heat, warm up 2 tablespoons of olive oil. Add chopped medium yellow onion and cook for 5–7 minutes until softened. Stir in minced garlic and sauté for another minute.

Fold in 1 cup of pumpkin puree and 1 can of crushed tomatoes, mixing well. Pour in 1 cup of vegetable broth, season with dried sage, thyme, nutmeg, salt, and pepper. Simmer on low heat, covered, for at least 15 minutes.

For an extra layer of richness, stir in ½ cup of heavy cream during the last 5 minutes of cooking. Turn off the heat once incorporated.

In a mixing bowl, combine 1 cup of ricotta cheese, well-drained frozen spinach, ½ cup of grated Parmesan cheese, 1 egg, and garlic powder. Season to taste with salt and pepper, then stir until evenly blended.

Preheat your oven to 375°F (190°C). Grease a baking dish with olive oil to prevent sticking.

Begin layering by spreading a thin layer of pumpkin sauce on the bottom of the dish. Add a layer of noodles, half of the ricotta filling, and a handful of shredded mozzarella. Repeat until all ingredients are used, finishing with sauce and mozzarella on top.

Cover the dish with aluminum foil and bake for 30 minutes. This helps meld the layers and develop flavors.

After 30 minutes, remove the foil and continue baking for an additional 15–20 minutes until the cheese is bubbly and golden brown.

Let the lasagna rest for 15–20 minutes before slicing. Garnish with fresh basil if desired.