Preheat oven to 350 degrees and grease an oven safe 9" x 9" baking dish. Or a 9"x13" baking dish if you are using 3/4 of a box.
Cook elbow macaroni as directed. Strain and set aside.
In a seperate pot add 1/2 cup cubed butter, cream cheese, cubed Velveeta cheese, 1 cup of shredded cheddar and 1/2 cup milk. Cook on low, and stir regularly until all ingredients are melted and blended well. 5-8 minutes. Salt and pepper to taste.
Once ingredients are combined and melted, add cooked macaroni and chopped bacon. Mix until well combined.
Place in greased 9"x13" baking dish.
Combine panko crumbs and 2 tbsp of melted butter. Sprinkle mixture evenly over the top of the mac and cheese. This will give the side dish a nice crunch. And sprinkle remaining shredded cheese and more crumbled bacon is you have extra. Bake at 350 degree for 20-25 minutes. Then enjoy!