Preheat oven to 325F
Grease a 9” x 13” casserole dish or a cast iron skillet. Set aside.
In a large stockpot, melt the butter over medium heat.
Meanwhile, in a separate pot, prepare the macaroni according to package directions.
Once the butter is melted, whisk in flour to form a roux (paste).
Whisk in the milk and cream and set heat to medium-high.
Whisk in 2 cups of the shredded cheddar cheese as well as the cream cheese and ranch seasoning. Continue whisking as the mixture cooks and thickens.
Drain the pasta but do not rinse.
When the cheese has completely melted into the sauce, pour the sauce over the cooked macaroni.
Add most of the chopped bacon and green onions and stir to combine.
Fold the macaroni and cheese into the prepared casserole dish.
Top with remaining 1 cup of cheese, plus reserved chopped bacon and green onions.
Bake for 25 minutes, or until the cheese on top is browned and completely melted.