Preheat the oven to 375°F (190°C).

In a large mixing bowl, combine the softened cream cheese, ranch seasoning, buffalo sauce, milk, shredded cheddar, and 1½ cups mozzarella.

Stir until the cheese mixture is creamy and evenly combined. If the cream cheese is very firm, allow it to soften further at room temperature before mixing.

Bring a large pot of salted water to a boil. Add the lasagna noodles and cook according to the package directions until al dente.

Drain the noodles and arrange them separately on a clean surface or parchment paper so they don't stick together.

Spread a thin layer of buffalo ranch cheese mixture over the bottom of a 9x13-inch baking dish.

Arrange a layer of lasagna noodles over the cheese mixture.

Spread some of the creamy cheese mixture over the noodles, followed by an even layer of shredded chicken.

Continue layering noodles, cheese mixture, and chicken until the ingredients are used, finishing with cheese mixture on top.

Sprinkle the reserved ½ cup mozzarella evenly over the assembled Cheesy Buffalo Ranch Chicken Lasagna.

Cover the baking dish tightly with aluminum foil and bake for 45 minutes.

Carefully remove the foil and bake for another 10 minutes, or until the cheese is melted, bubbling, and lightly golden.

Remove the lasagna from the oven and let it rest for 8–10 minutes before slicing.

Garnish with chopped green onions and optional ranch dressing or blue cheese crumbles before serving.