Heat 2 tablespoons of olive oil in a large pan over medium heat. Sauté 8 cloves of minced garlic until fragrant, about 1 minute.

Stir in 4 cups of pumpkin puree and 2 cups of milk, blending until smooth. Season with 1 teaspoon of salt, ½ teaspoon of dried oregano, and 1 teaspoon of dried basil. Let simmer for about 5 minutes.

Add 2 tablespoons of vinegar or lemon juice to the sauce to brighten the flavors.

Fill a large pot with salted water and bring it to a boil. Cook the 12 lasagna noodles according to package instructions for about 8-10 minutes until al dente.

Drain the noodles and lay them flat on a clean surface.

In a skillet, brown ½ pound of ground meat over medium heat, seasoning with ½ teaspoon of dried sage, salt, and pepper. Stir in 3 cups of thawed spinach and 12-16 ounces of ricotta cheese.

Let the filling cool slightly before assembling the lasagna.

In a 9x13 inch baking dish, pour a layer of the creamy pumpkin sauce. Layer noodles over sauce, followed by half of the meat-spinach mixture. Continue layering, finishing with noodles, sauce, and mozzarella on top.

Preheat oven to 425ºF (220ºC). Cover the lasagna with foil and bake for 30 minutes. Remove foil and bake for an additional 5 minutes until cheese is bubbly.

Let the lasagna cool for at least 10 minutes before cutting and serving.