Preheat oven to 350°F. Spray a 9×13-inch baking dish with nonstick cooking spray. Set aside.
In a small bowl, mix paprika, salt, pepper, and garlic powder. Sprinkle the seasoning evenly over both sides of the chicken breasts and rub it in well.
Add flour to a small plate or bowl.
Dredge each seasoned chicken breast in flour, coating all sides. Shake off excess and set aside.
In a large skillet over medium heat, melt 4 tablespoons of the butter. Working in batches if needed, add the chicken breasts. Cook 4 minutes per side until golden and crispy (they don’t need to be fully cooked through yet). Transfer the chicken to the prepared baking dish.
In the same skillet, melt the remaining 2 tablespoons butter. Add diced onion and cook for 5 to 8 minutes, until softened.
Stir in the ranch seasoning and cook for 30 seconds.
Add cream of chicken soup and heavy cream, whisking until smooth.
Stir in 1 cup of the shredded cheddar cheese until melted and creamy.
Mix in about ½ cup of the cooked bacon, reserving the rest for topping.
Pour the ranch cheese sauce evenly over the chicken in the baking dish.
Bake uncovered for 40 minutes.
Remove from oven, sprinkle with remaining 1 cup cheddar cheese and remaining bacon.
Return to oven and bake for another 5 to 10 minutes, until the cheese is melted and the chicken reaches an internal temperature of 165°F.
Let rest for 5 to 10 minutes before serving. Spoon extra sauce over each portion.