Preheat and prep: Heat oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish.
Cut the chicken: Cube chicken into 1-inch pieces or slice into thin cutlets for faster cooking.
Pat dry and season lightly with salt and pepper.
Make the buffalo ranch sauce: In a bowl, whisk softened cream cheese, heavy cream, buffalo sauce, melted butter, ranch seasoning, and garlic until smooth. If it’s too thick, add a splash more cream.
Assemble the bake: Scatter chicken evenly in the baking dish. Add celery and half the green onions.
Pour the sauce over the top and toss gently to coat.
Add the cheese: Sprinkle shredded cheese evenly over the chicken mixture.
Bake: Place in the oven for 22–28 minutes, or until the chicken is cooked through (165°F/74°C) and the edges are bubbling. If you want more color, broil for 2–3 minutes at the end.
Rest and garnish: Let the bake rest for 5 minutes so the sauce thickens. Top with remaining green onions and, if you like, crumbled blue cheese or a drizzle of ranch.
Serve: Pair with a simple side like roasted broccoli, zucchini noodles, or a crisp salad.
Or portion into meal-prep containers for the week.