In a large skillet, heat olive oil over medium heat and cook the sausages until golden brown. Crumble the sausages a little in the pan as they cook and drain the excess fat.
Tip in the diced tomatoes, canned tomatoes, oregano, basil, crushed chilli flakes, garlic powder and season with salt and pepper.
Stir well and bring this mixture to a simmer. Add the pasta and two cups of water to the skillet.
Bring it to a boil, cover it and cook over medium heat for about 8-10 minutes or until the oasta is completely cooked through.
Remove from heat; tip in the shredded mozzarella and parmesan making sure you stir it all the while. Add dollops of ricotta on top and cover hot until the cheese melts a little.