Preheat oven to 375 F.

In a large, deep, oven-safe skillet, heat the olive oil over medium heat. Add the Italian sausage to the skillet and brown, breaking up into small pieces with a wooden spoon. When the sausage is almost done, add the minced garlic.

Pour in the tomato sauce, tomatoes, oregano, salt, and water. Use a wooden utensil to scrape the browned bits off the bottom of the pan, and stir together the sauce. 

Add the rigatoni and tomatoes to the skillet and mix in. Cover and simmer for 15 minutes. 

Remove from heat. Uncover skillet; stir in the the pepperoni and fresh basil. Fold in half of the bocconcini, press them under the top surface of the pasta as much as possible. Top with the remaining mozzarella. 

Transfer to preheated oven and back for 15 minutes, when cheese is melted and golden brown. Serve immediately.