Preheat and prep: Heat your oven to 350°F (175°C). Lightly grease a 9x13-inch baking dish.
Cook your base: If you’re using pasta, cook it to al dente, drain, and set aside. If using cauliflower, steam until just tender, then pat dry.
Make the creamy sauce: In a large bowl, beat the cream cheese until smooth.
Stir in sour cream, ranch seasoning, garlic powder, onion powder, smoked paprika, and chicken broth or milk. Mix until creamy and well combined.
Add the good stuff: Fold in 1 1/2 cups cheddar, the shredded chicken, half the bacon, and the peas or broccoli if using. Taste and season with salt and pepper.
Combine and assemble: Gently fold the pasta or cauliflower into the sauce mixture.
Spread evenly in the prepared baking dish.
Top it: Sprinkle the remaining 1/2 cup cheddar over the casserole. If you like a crunchy top, mix crushed crackers or panko with melted butter and scatter over the cheese.
Bake: Bake for 20–25 minutes, until the casserole is hot and bubbling and the top is lightly golden.
Finish and serve: Remove from the oven and let it rest for 5 minutes. Top with the remaining bacon and sliced green onions.
Serve warm.