Start by bringing a large pot of salted water to a boil. Add the 8 oz penne pasta and cook according to the package instructions until al dente, about 10-12 minutes. Drain the pasta using a colander and set aside.
While the pasta is cooking, heat 2 tablespoons of olive oil in a large skillet over medium heat. Add the turkey sausage, breaking it up with a wooden spoon as it cooks. Cook until browned and cooked through, about 6-8 minutes. Remove the sausage from the pan and set aside, leaving the drippings in the skillet.
In the same skillet, add the diced onion and cook for 3-4 minutes until softened. Add the minced garlic and sauté for another minute until fragrant, being careful not to burn it.
Pour in 1 cup of heavy cream and 1/2 cup of chicken broth, stirring to combine with the onions and garlic. Add 1 teaspoon of Italian seasoning, and season with salt and pepper to taste. Let the sauce simmer gently for 3-5 minutes until it thickens slightly.
Stir in the halved cherry tomatoes and the cooked turkey sausage. Cook for another 2-3 minutes so the tomatoes soften slightly and the flavors meld together.
Add the drained penne pasta to the skillet, tossing everything together to coat the pasta evenly in the creamy sauce. Stir in 1/2 cup of grated Parmesan cheese for richness and extra flavor.
Remove the skillet from heat and sprinkle fresh basil leaves over the top before serving to add a fresh, herbaceous note.