Preheat oven to 350° F and prepare an 8 X 8-inch baking dish by spraying it with cooking spray.

Cook rigatoni according to package directions in a large pot of water, salted generously. Follow directions to cook it to 'al dente,' then drain the salted water. Set the cooked pasta aside. Drizzle a little olive oil over the rigatoni to keep it from sticking.

In a large skillet over medium-high heat, sauté onion and minced garlic in olive oil until translucent, about 2-3 minutes.

Add sausage and heat until thoroughly cooked. Remove from heat and stir in basil, salt, and pepper to taste. Place sausage mixture into a large bowl and set it aside.

Remove the cloves of roasted garlic by gently squeezing them from the skins, then place them into a small bowl. Mash the cloves with a fork.

In a medium saucepan, melt the butter on low to medium heat. Add the cream and roasted garlic, and heat to very warm, but DO NOT boil.

Lower heat and mix in the Parmesan cheese, salt, and pepper, whisking constantly until the cheese has melted.

In a small bowl, combine 2 teaspoons of flour and 2 tablespoons of heavy cream until well combined. Pour this into the cheese sauce, stirring and heating until the mixture thickens.

Pour the creamy sauce over the sausage and stir until well-coated. Add rigatoni and mix thoroughly. Pour contents into the prepared baking dish. Sprinkle shaved Parmesan cheese on top of the pasta. Bake for 30 minutes until bubbly and lightly browned.