Preheat oven to broil.
In a large oven-proof skillet, brown sausage over medium-high heat until crumbly. If using onions and peppers add the skillet. Cook the veggies with the sausage for a few minutes until they just start to get soft. Stir in oregano, basil, and garlic powder and cook for another minute. Add both cans tomato sauce, canned tomatoes with juice, water and pasta. Bring to a boil. Cover and reduce heat to a low simmer until pasta is cooked through and most of the sauce has cooked away, about 10 to 14 minutes. Stir occasionally so pasta doesn’t stick. Remove from heat. Sprinkle the top with mozzarella cheese and pepperoni slices. Place under broiler until cheese melts and browns. Serve warm.