Preheat and prep: Heat your oven to 375°F (190°C). Grease a 9x13-inch baking dish.

Cook or dry the cauliflower rice: If using frozen, thaw fully and squeeze out excess liquid with a clean towel. If using fresh, saute in a dry skillet for 5–7 minutes to steam off moisture. Dry rice prevents a watery casserole.

Soften the sauce base: In a large bowl, microwave cream cheese and butter (if using) for 20–30 seconds to soften. Stir until smooth.

Build the sauce: Whisk in sour cream, buffalo sauce, ranch seasoning (or dressing), garlic powder, and onion powder. Taste and add salt and pepper as needed.

Combine the mix-ins: Fold in the cooked chicken, cauliflower rice, diced celery, and green onions. Add 1 cup of shredded cheese and stir to combine.

Assemble: Spread the mixture evenly into the prepared baking dish. Sprinkle the remaining 1 cup of shredded cheese over the top. Add blue cheese crumbles if using.

Bake: Bake for 22–28 minutes, until the casserole is hot and bubbling and the cheese is melted.

Broil for color (optional): Broil for 1–2 minutes to lightly brown the top. Watch closely to avoid burning.

Finish and serve: Let it rest 5–10 minutes to set. Top with extra buffalo sauce, a drizzle of ranch, and more sliced green onions. Serve warm.