If making in the oven, preheat your oven to 350 °F.
Cook the pasta according to the package directions to a firm al dente. Remember, you are cooking it even further in the oven or crockpot, you don't want mush.
Fry the ground beef and Italian sausage in a large skillet until browned. Mix in the onion and mushrooms and cook until soft. Add in the garlic, saute for 2-3 minutes.
Stir in the Italian seasoning, diced tomatoes and tomato sauce. Simmer briefly, then set aside and cool for 10 minutes.
Grease or spray a 9x13 casserole dish or the inside of the slow cooker. Spread a little bit of the sauce on the bottom of the dish/slow cooker, then top with the pasta.
Sprinkle the Italian blend cheese over the pasta, then pour the remaining sauce over the casserole.
Cover and cook in the oven for 45 minutes or in the slow cooker on low for 1 1/2 - 2 hours. When ready, uncover, sprinkle the cheddar cheese on top and then cover again until melted.
Serve and enjoy!
Video
Notes
If you have a slow cooker where "low' is super hot, cut the time to 1 1/2 hours. The slow cooker method is great for when you don't want to use the oven but it's not an all day recipe. As with almost all ground beef recipes that use the slow cooker, you have to cook the ground beef first.