Preheat your oven to 350°F. Spray a 13x9-inch (3-quart) glass baking dish with cooking spray and set aside.
In a large nonstick skillet, melt the butter over medium-high heat. Cook the mushrooms in the butter for 8-10 minutes, stirring occasionally, until soft and browned.
Once cooked, add in the chicken broth and deglaze the pan, scraping any brown bits off of the bottom.
Add in the rest of the sauce ingredients and combine. Heat up in the pan, stirring to ensure it doesn't burn.
Place the cooked spaghetti in a large bowl, then pour the skillet sauce over top, combining thoroughly. Once the pasta is covered, transfer to the 9x13 pan.
Mix the bread crumbs, seasoning and mozzarella together, and sprinkle evenly over dish. Transfer to the pre-heated oven and bake for 30-35 minutes OR until the casserole is bubbling and the topping is browned.
Cool for 5 minutes before serving.
You can use two cans of mushroom soup if you prefer it
Add in a few handfuls of fresh spinach while sauteing the mushrooms and fry up to add into the casserole