In the bowl of a stand mixer, add the cream cheese, ranch, buffalo sauce, milk, & 1 1/2 cups of each cheese. Mix together, just until evenly combined.
Spray a 9x13" baking dish with non stick cooking spray. Spread 1/4 of the cheese mixture evenly out over the bottom of the pan.
Cover with a layer of pasta, overlapping the noodles as necessary to create a smooth, solid layer.
Spread another 1/4 of the cheese mixture evenly out over the pasta. Top with half the chicken. Repeat with another layer of pasta, cheese mixture, and chicken. Top with the remaining noodles. Spread the rest of the cheese mixture evenly out over top.
Sprinkle the remaining cheese evenly out over top. Cover the dish tightly with foil.
Bake at 375 degrees for 45 minutes. Remove the foil. Bake an additional 10 minutes, or until the cheese is hot & bubbly.
Remove the lasagna from the oven. Let rest for 8-10 minutes. Slice and serve, topped with a drizzle of ranch, sliced green onions, and blue cheese crumbles- as desired.