Preheat the oven to 350 degrees Fahrenheit. Spray a 9 by 13 inch baking dish with cooking spray and set aside.
Bring a large pot of water to a roaring boil. Season with salt and add the penne pasta, boiling for less than 2 minutes of the suggested cooking time. For example, if the box suggests boiling for 10 minutes, boil for 8 minutes.
16 ounces penne pasta, 1 teaspoon kosher salt
Preheat a large skillet over medium heat. Add the Italian sausage, breaking it up as you cook. When it is completely broken up and beginning to brown, add the green pepper and garlic. Season with salt and pepper. Sauté until the peppers have begun to soften, about 5 to 7 minutes. Drain the excess grease.
1 pound Italian sausage, 2 cloves garlic, 1 green pepper, 1 teaspoon kosher salt, 1/4 teaspoon black pepper
In a large bowl, combine the cooked pasta, sausage mixture, marinara sauce, and 1/2 cup cheese. Pour into the prepared baking dish.
24 ounces marinara sauce, 2 1/2 cups shredded mozzarella
Top with the remaining 2 cups of mozzarella, pepperoni, black olives, and Parmesan.
2 1/2 cups shredded mozzarella, 1 1/2 ounces pepperoni, 1/4 cup sliced olives, 1/4 cup shredded Parmesan
Bake, covered, for 20 minutes. Remove cover and bake for an additional 5 to 10 minutes or until the cheese is bubbly and beginning to brown.