Heat 1 tablespoon of olive oil and the bacon in a large pan over medium heat. Cook, flipping occasionally, until the bacon is crispy, about 12 to 15 minutes.

Remove the bacon to a paper towel lined plate. Remove 3 tablespoons of the bacon fat to a heat proof bowl and set aside, leaving 1 tablespoon of bacon fat in the pan. When the bacon is cool enough to handle, crumble or chop the bacon into small pieces and set aside.

Add the spinach to the pan, toss to coat in the bacon fat, cover and cook over medium-high heat, until it wilts. 1 to 2 minutes. Remove spinach to a plate and set aside to cool. (This will be eventually added to the ricotta mixture.)

Dry any excess moisture in the pan with a paper towel, then add the 3 tablespoons of reserved bacon fat into the pan. Add the mushrooms and 1 teaspoon salt to the pan with the bacon fat, and cook over medium-high, stirring occasionally, until the mushrooms are beginning to brown, about 8 to 10 minutes.

Add the sausage, onion, carrot, celery and cook for 4 minutes. Add the garlic and the Italian seasoning and cook for 2-3 minutes more until the vegetables are soft, and the mushrooms have browned.

Pour in the wine and deglaze the pan, scraping off any tasty stuck bits. Simmer until the liquid has mostly evaporated, 4 to 5 minutes.

Add in the pasta sauce, tomato paste, and simmer uncovered until slightly thickened, 10 to 12 minutes.

Stir in the reserved bacon, turn off the heat and set aside.

While the sauce is thickening, preheat the oven to 350°F and butter a 9”x13” baking dish.

In a large pot of salted water, boil the lasagna noodles, according to package directions for al dente. Drain the noodles, rinse under cold water, and set aside. (Brushing a little olive oil on the noodles will help keep them from sticking but is completely optional).

While the noodles cook, whisk the egg and ¼ teaspoon salt in a large bowl. Add the ricotta and stir to combine. Next, add 1 cup mozzarella, ½ cup parmesan cheese, and the parsley. Squeeze the excess water out of the spinach, then coarsely chop the spinach and add it to the egg mixture. Stir until completely incorporated.

Remove the foil and sprinkle with the remaining 2 ½ cups mozzarella cheese and ½ cup Parmesan cheese. Bake for an additional 15 minutes or until browned and bubbly. Broil for 2-3 minutes if desired but watch carefully to ensure it does not burn.

Allow the lasagna to rest for 15 minutes before serving.