Spray an oven-safe skillet with nonstick cooking spray. Add the cooked chicken breast, Italian seasoning, garlic powder, onion powder, salt, and black pepper. Stir and cook for 2–3 minutes, just until the chicken is heated through and coated in the seasonings.

Add the gnocchi and marinara sauce. Stir everything together and bring to a gentle simmer.

Cook for about 5–7 minutes, or until the gnocchi is tender and the sauce is hot and slightly thickened. Stir occasionally.

Remove the skillet from the heat and sprinkle the mozzarella and Parmesan evenly over the top.

Combine the panko breadcrumbs with 1 teaspoon melted light butter. Sprinkle the mixture evenly over the cheese.

Place the skillet under the broiler for 1–2 minutes, watching closely, until the cheese is melted and bubbly and the panko is golden brown.

Let the Chicken Parmesan Gnocchi rest for a few minutes before serving. Garnish with fresh parsley if desired.