Preheat your oven to 350°F.
Season both sides of the chicken breasts generously with salt, black pepper, garlic powder, onion powder, and paprika. Do not be shy here. The seasoning builds the base flavor for the entire dish.
Lay the seasoned chicken breasts evenly in a 9x13 baking dish.
In a mixing bowl, combine one can of cheddar cheese soup with milk, filling the empty soup can about halfway. Whisk until smooth.
Season the cheese mixture generously with onion powder, garlic powder, paprika, mustard powder, and black pepper. This is one of those moments where you truly follow your heart and adjust to your taste. Whisk again until well blended.
Stir in 4 ounces of grated sharp cheddar cheese. This deepens the cheesy flavor and gives the sauce more body.
Spread about half of the cheese mixture evenly over the chicken breasts in the baking dish.
Microwave the frozen broccoli according to the bag instructions. Once cooked, add the broccoli to the remaining cheese mixture. Stir well and break up any large pieces so the broccoli distributes evenly.
Spoon the broccoli and cheese mixture over the top of the chicken, spreading it evenly across the dish.
In a small bowl, combine the crushed Ritz crackers with the melted butter. Stir until the crumbs are coated. Sprinkle about half of this mixture over the top of the casserole for a light buttery crunch or as much as you want.
Bake at 350°F for 25 to 30 minutes, or until the chicken is fully cooked and the sauce is bubbling around the edges.
Let the dish rest for a few minutes before serving.