Preparation Steps

• Bring a 5 to 6 quart pot of water to a boil over medium-high heat. Add the dry pasta and cook al dente, according to package directions. Drain well and set aside.
• In a deep 10-inch skillet over medium heat, add the sausage, green peppers, onion, sliced fresh mushrooms, minced garlic, and olive oil. Stir often to break up the sausage as it cooks for about 5 to 7 minutes until the onions, peppers, and mushrooms are softened and the sausage is cooked through.
• Lower the heat to medium-low. Add the Italian seasoning to the meat mixture and stir.
• Add the spaghetti sauce to the sausage and vegetables. Pour ¼ cup of water into the sauce jar and shake. Pour the remaining sauce into the skillet and stir. Allow the sauce to simmer for about 2 to 3 minutes, stirring often. Remove the pan from the heat.
• Next, add the cooked rotini to the sauce and stir to completely coat the pasta.
• Spray a 6 to 7 quart crock pot with nonstick cooking spray.
• Layer half of the pasta and sauce into the crockpot. Sprinkle 1.5 cups of mozzarella over the pasta, and arrange half of the sliced pepperoni over the cheese. Repeat the layers with the remaining pasta, 1.5 cups cheese, and remaining sliced pepperoni. Cover with the crock pot lid and cook on low for 3.5 hours.
• At the 3.5-hour mark, sprinkle the remaining 1 cup of shredded mozzarella over the top of the pepperoni. Cover and cook for an additional 30 minutes.
• Just before you're ready to serve, garnish with the chopped parsley. Serve while hot.