To roast the butternut squash, preheat the oven to 425F. Lightly spray the butternut squash with an olive oil mister and sprinkle with salt and pepper. Roast the butternut squash for about 30 minutes.

Meanwhile, set a non-stick skillet over medium heat and heat olive oil. Then add cloves of garlic and a pinch of chili flakes.

Heat until garlic begins to soften, about 2 minutes. Add in spinach and sauté until spinach is completely wilted. Set aside on a paper towel to drain.

Prepare pasta according to package directions. Drain and set aside.

To caramelize the onions, melt 1 tablespoon of butter in a large nonstick skillet over medium heat. Add the onions with a tsp of salt and cook down for about 20-30 minutes, until onions turn brown. Set aside.

To make the creamy sauce, bring the milk, nutmeg, sage, ½ tsp pepper, and remaining chili flakes to a simmer.

In a separate saucepan, make the roux by melting the remaining tbsp. of butter and then add in the flour. Stir until doughy (about one minute).

Whisk the milk into the butter and flour mix (the roux). It should be smooth and velvety, not chunky or too thick. If it is, just add some more milk to thin it out. Add in the Parmesan, and whisk until smooth. Set aside.

In a small bowl, combine ricotta, basil, remaining garlic, salt, pepper, and chili flakes.

Now, preheat the oven to 375.

In a large, 5qt casserole dish, place a layer of noodles, spinach, butternut squash, and onions, and then dot with a third of ricotta. Then cover with about 1/4 of the cream sauce. Repeat with the remaining ingredients until are used up.

Then top evenly with the sliced mozzarella.

Bake for about 20-25 minutes, or until bubbling.

Turn the broiler on and bake for another 5 minutes, or until browned on top.

Remove from oven and let cool for about 15-20 minutes.