1. Preheat the oven to 375°F (190°C).

2. Cook the spaghetti according to the package instructions until al dente. Drain and set aside.

3. In a large skillet, melt the butter over medium heat. Add the chicken thighs and cook until browned on both sides, about 5 minutes per side. Remove the chicken from the skillet and set aside.

4. In the same skillet, add the cream of chicken soup and 1/2 cup of water. Stir well to combine.

5. Return the chicken thighs to the skillet and spoon some of the soup mixture over them. Cover the skillet with a lid and simmer for 10 minutes, or until the chicken is cooked through.

6. Remove the chicken from the skillet and shred it into bite-sized pieces using two forks.

7. Add the shredded chicken back to the skillet with the remaining soup mixture. Stir well to combine.

8. In a separate small bowl, melt 2 tablespoons of butter in the microwave. Add the panko bread crumbs and stir until coated.

9. Spread half of the cooked spaghetti in a greased baking dish. Top with half of the creamy chicken mixture. Repeat with another layer of spaghetti and chicken mixture.

10. Sprinkle the panko bread crumb mixture over the top of the casserole.

11. Bake in the preheated oven for 20-25 minutes, or until golden brown and bubbly.

12. Serve hot and enjoy!