Bring a large pot of salted water to a boil. Add the 8 ounces of spaghetti and cook according to package instructions until al dente. Drain and set aside. Toss the cooked spaghetti briefly with a little olive oil to prevent sticking.
Pat the chicken breasts dry with paper towels. In a shallow bowl, combine the Italian seasoned breadcrumbs, garlic powder, dried oregano, salt, and pepper. Lightly brush each chicken breast with olive oil on both sides, then coat evenly with the breadcrumb mixture.
Heat 2 tablespoons of olive oil in a large skillet over medium heat. Add the chicken breasts and cook for about 4-5 minutes per side, or until golden brown and cooked through (internal temperature should reach 165°F or 74°C). Remove from heat and let them rest for a few minutes before slicing into strips or bite-sized pieces.
Preheat your oven to 375°F (190°C). In a large mixing bowl, combine the cooked spaghetti with 1 1/2 cups of marinara sauce, tossing until the pasta is evenly coated. Spread half of the spaghetti mixture evenly in the bottom of your baking dish.Layer the sliced chicken breasts over the spaghetti. Pour the remaining marinara sauce over the chicken, then top with the remaining spaghetti. Sprinkle the shredded mozzarella and grated Parmesan evenly over the top. Cover the baking dish loosely with aluminum foil and bake for 20 minutes. After 20 minutes, remove the foil and bake for an additional 10 minutes, or until the cheese is bubbly and golden brown.
Once baked, remove the dish from the oven and let it cool for 5 minutes. Garnish with fresh basil leaves for a bright, herbaceous touch. Serve warm and enjoy!