Preheat your oven to 375°F (190°C).

In a large pot of salted boiling water, cook the lasagna noodles until al dente, about 8 to 10 minutes. Drain and lay flat.

In a mixing bowl, combine ricotta cheese, chopped spinach, minced garlic, dried oregano, salt, and pepper. Stir until well mixed.

Spread a thin layer of pumpkin puree on the bottom of a 9x13-inch baking dish.

Lay down three lasagna noodles, then spread half of the ricotta-spinach mixture over the noodles. Follow with another layer of pumpkin puree, mozzarella, and parmesan.

For the final layer, place three more lasagna noodles on top, cover with remaining pumpkin puree, mozzarella, and parmesan.

Bake uncovered for about 30 minutes, or until the cheese is bubbly and golden brown.

Allow the lasagna to rest for 10 minutes before slicing and serving.