Preheat your oven to 375°F (190°C). Lightly spray a 9x13-inch baking dish with cooking spray.
In a large bowl, beat the softened cream cheese until smooth.
Add Greek yogurt and whisk until combined and creamy.
Stir in the ranch seasoning, garlic powder, onion powder, and smoked paprika. Whisk in the chicken broth a little at a time until the mixture is smooth and scoopable, not runny.
Fold in 1 cup of the shredded cheddar, half of the bacon, and half of the green onions. Taste and season with salt and pepper.
Add the chicken and broccoli (if using).
Mix until everything is evenly coated with the creamy ranch mixture.
Spread the mixture into the prepared baking dish. Top with the remaining 1/2 cup cheddar.
If you like a crunchy top, sprinkle on the crushed chips or crumbs now.
Bake for 20–25 minutes, until the casserole is hot and bubbling at the edges and the cheese is melted.
Remove from the oven and top with the remaining bacon and green onions. Let it rest for 5 minutes to set slightly before serving.