Step 1

Preheat oven to 375°F and grease a 9x13-inch baking dish with nonstick spray.

Step 2

In a small bowl, whisk together sour cream, 1/2 cup of the Parmesan, salt, pepper, oregano, basil, garlic powder, and cornstarch.

Step 3

Arrange chicken breasts in baking dish, top each with a slice of mozzarella, and coat with the sour cream mixture.

Step 4

Sprinkle remaining Parmesan over the top and bake until chicken is cooked through and sauce is bubbly, about 1 hour.