Heat your oven: Preheat to 375°F (190°C). Lightly coat a 9x13-inch baking dish with cooking spray.
Make the creamy base: In a large bowl, whisk Greek yogurt, cream cheese, chicken broth, ranch seasoning, garlic powder, onion powder, and smoked paprika until smooth.
Taste and season with a pinch of salt and pepper.
Fold in the good stuff: Stir in 1/2 cup cheddar, broccoli, bell pepper, and peas or corn if using. Mix until evenly combined.
Add the chicken: Gently fold in the shredded chicken, coating it well with the sauce. Spread the mixture into the prepared baking dish.
Top it off: Sprinkle the remaining 1/2 cup cheddar over the casserole.
In a small bowl, toss panko with olive oil and a pinch of salt. Scatter the panko and the crumbled turkey bacon over the top.
Bake: Place on the center rack and bake for 18–22 minutes, until hot and bubbling at the edges and the top is golden.
Finish and serve: Let it rest for 5 minutes. Sprinkle with green onions.
Serve warm with a simple side salad or roasted veggies.