Bring water to a boil in a pot for the pasta.

Add cavatappi pasta to the boiling water and cook according to package directions.

While pasta is cooking, melt butter in a saucepan over medium heat.

Add flour to the melted butter and stir to form a light roux.

Gradually stir in milk, ensuring no lumps form.

Add salt, pepper, parmigiano-reggiano cheese, and garlic powder to the sauce.

Stir in shredded roasted chicken and freshly chopped basil.

Reduce heat to low and simmer until the sauce thickens to your desired consistency.

Turn heat to low as the sauce begins to come together to prevent burning.

Drain the cooked pasta and add it to the saucepan with the cream sauce.

Toss to coat the pasta evenly with the sauce.

Serve immediately.