Bring a large pot of salted water to boil. Cook the pasta according to package directions (usually 8-11 minutes) until al dente. Drain and set aside.

While pasta cooks, heat a large skillet over medium heat and add the olive oil. Once shimmering, crumble in the Italian sausage, breaking it into bite-sized pieces with a wooden spoon. Cook for 5-7 minutes, stirring occasionally, until deeply browned and no pink remains. Transfer the cooked sausage to a plate.

In the same skillet with the drippings, add the minced garlic and chopped sun-dried tomatoes. Sauté for 1-2 minutes until the garlic turns golden and fragrant. Add about 1/4 cup of the chicken broth and scrape up all the browned bits from the bottom of the pan.

Pour in the remaining chicken broth and heavy cream, stirring to combine. Add the grated parmesan and whisk until the cheese melts completely and the sauce is smooth. Reduce heat to medium-low and simmer gently for 5 minutes until the sauce thickens enough to coat the back of a spoon.

Return the cooked sausage and drained pasta to the skillet. Toss everything together using tongs until every piece of pasta is coated in the sauce. Season with salt, black pepper, and red pepper flakes if using. Taste and adjust seasoning as needed.

Serve immediately while hot, topped with torn fresh basil leaves and extra parmesan if desired.