Preheat your oven to 350°F (175°C).

Cook the spaghetti in a pot of salted boiling water according to package directions; usual time is 8-10 minutes.

Sear the chicken breasts in a skillet until golden and cooked through, about 6-7 minutes per side. Once cool, shred into bite-sized pieces.

Crisp the bacon in the same skillet until it's perfectly crispy, then crumble it.

Mix in a large bowl the cream of chicken soup, sour cream, and half the cheddar cheese until smooth. Then, add the cooked spaghetti, shredded chicken, and crumbled bacon; stir gently.

Transfer the mixture to a greased 9x13-inch baking dish, topping it with the remaining cheese, crumbled bacon, and green onions.

Bake for 20-25 minutes, or until the cheese is melted and bubbly. Let it sit for a few minutes before serving.