Preheat the oven to 375°F.

Lightly spray a 9×13 baking dish.

Fill a medium-sized saucepan ¾ of the way with water. Bring to a low rolling boil and add the elbow macaroni. Cook the macaroni until it is all done. Drain the macaroni and set it aside.

In a medium-sized skillet, add the butter and diced onions. Cook over medium to high heat, stirring the onions with a wooden spoon to ensure even cooking for about 5 to 7 minutes. They should be translucent and starting to turn golden/light brown. Remove from the heat and set aside.

In a medium-sized mixing bowl, add the softened cream cheese, cream of chicken soup, sour cream, milk or half-and-half, and package of ranch dressing powder.

Using a handheld mixer, combine the sour cream mixture on medium speed until creamy.

Continue mixing on low and add the kosher salt, black pepper, and onion powder. Mix until well combined.

Transfer the sour cream mixture to a large mixing bowl. Add in the cooked macaroni, the cubed chicken breast, cooked yellow onion, 1½ cups of cheddar cheese, and ¾ of a cup of cooked bacon. Using a large wooden spoon, stir until all the ingredients are completely combined.

Pour the chicken mixture into the prepared baking dish and spread evenly.

Sprinkle the remaining shredded cheddar cheese, bacon, and the thinly sliced green onion.

Bake for 35 to 40 minutes, until the top layer of cheese is melted and gooey.