Preheat the oven broiler.
Cut the chicken breasts into bite-size pieces and toss with the herb and garlic seasoning until evenly coated.
Heat the olive oil in a 12-inch oven-safe nonstick skillet over medium-high heat. Add the seasoned chicken and cook, stirring occasionally, until golden brown on the outside and cooked through, about 5 minutes.
Add the pasta, spaghetti sauce, water, and red pepper flakes to the skillet with the chicken. Bring to a boil, then cover and reduce heat to low; simmer until the pasta is tender, about 15–18 minutes, stirring occasionally to prevent sticking.
Stir 6 tablespoons of the grated Parmesan into the cooked pasta and simmer over low for 5 minutes to thicken the sauce.
Top the pasta evenly with the shredded mozzarella.
In a small bowl, combine the panko, melted butter, remaining grated Parmesan and garlic powder until moistened, then sprinkle the mixture over the mozzarella layer.
Place the skillet under the preheated broiler and heat until the breadcrumbs are toasted and the cheese is melted and bubbly, watching closely so it doesn't burn, about 2–4 minutes.
Remove from the oven and let rest for a couple of minutes before serving.