Fry bacon, set aside. Saute onion and mushroom in a little bit of olive oil, salt and pepper. Add both meets and brown, drain off any grease. Add seasonings, mix well and let cook for a minute before adding spaghetti sauce. Simmer on low for a couple of hours.
Boil water with 2 tbls of salt, cook pasta until aldente, drain, reserving 1 cup of pasta water.
In a big medium size bowl, whisk together milk, sour cream, eggs, parmesan cheese, salt and pepper. Add pasta, mixing well, then stir in a generous handful of mozz cheese, adding reserved pasta water, as needed per consistancy you want.
Preheat oven to 350. Pour pasta mixture into a 13x9 baking dish, spread evenly. Pour meat sauce over top, top with mozz cheese, bacon and pepperoni. Bake uncovered 30 minutes, or until cooked through. Remove and cover with foil and let set for 10 minutes serving. Enjoy!
***Can put under broil on hi for a few if you like your cheese that way, I did, it was yummy!