Heat olive oil in a large pot over medium heat. Add sausage and brown for 3 minutes, breaking it up into bite-size pieces.

Add onion, garlic, oregano, salt, pepper, and red pepper flakes, and cook until onion is softened and sausage is browned, about 7 more minutes.

Stir in tomato paste and cook for 2 minutes more.

Add diced tomatoes, bay leaves, and chicken stock. Bring just to a boil, then reduce heat and simmer for 15 minutes.

Meanwhile, prepare pasta in a separate saucepan according to package directions, just to al dente. Do not overcook. Drain.

In a medium bowl, create the 'cheesy yum' by combining the ricotta, Parmesan, salt, and pepper. Set aside.

Stir fresh basil into soup right before serving. Add cooked pasta to individual bowls and ladle soup over the top. Serve with dollops of cheesy yum plus additional shredded mozzarella.

Heat a large nonstick skillet over medium-high heat and add oil. Once hot, add sausage and brown for 3 minutes.

Add onion, garlic, oregano, salt, pepper, and red pepper flakes, and cook until onion is softened and sausage is browned, about 7 more minutes.

Stir in tomato paste and cook for 2 minutes more.

Transfer sausage mixture to slow cooker and add diced tomatoes, bay leaves, and chicken stock. Cover and set to low for 8 hours or high for 4 hours.

In a medium bowl, create the 'cheesy yum' by combining the ricotta, Parmesan, salt, and pepper. Set aside.

About 30 minutes before soup is ready, add pasta to slow cooker. Cover and cook until pasta is just al dente.

Stir fresh basil into soup right before serving. Then add soup to individual bowls with dollops of cheesy yum plus additional shredded mozzarella.

Press SAUTE on the Instant Pot and add oil. Once hot, add sausage and onion and cook for 5 minutes.

Stir in garlic, oregano, salt, pepper, and red pepper flakes, and cook until onion is softened and sausage is browned, about 3 more minutes.

Stir in tomato paste and cook for 2 minutes more. Scrape bottom of pot very well. Press CANCEL.

Stir in diced tomatoes, bay leaves, and chicken stock. Press SOUP and cook for 15 minutes.

Press CANCEL and quick release pressure. Add pasta, submerging it below the soup broth. Press SOUP and cook for 8 minutes more.

Press CANCEL and then quick release pressure.

While pasta is cooking, create the 'cheesy yum' by combining the ricotta, Parmesan, salt, and pepper in a mixing bowl. Set aside.

Stir in fresh basil and then serve. Add soup to individual bowls with dollops of cheesy yum plus additional shredded mozzarella.