Prep the oven and pan: Heat the oven to 400°F (200°C). Lightly oil a 9x13-inch baking dish.
Season the chicken: Pat the chicken dry. Season both sides with salt, pepper, smoked paprika, and onion powder.
Place in the baking dish.
Make the creamy topping: In a bowl, stir together softened cream cheese, mayonnaise, 1 cup of shredded cheddar, Parmesan, garlic, chopped jalapeños, and green onions. Mix until smooth. Taste and add salt and pepper if needed.
Spread it on: Divide the mixture over the chicken breasts, smoothing it into an even layer over each piece.
Add the good stuff: Sprinkle remaining 1/2 cup cheddar over the top.
If using bacon, scatter it evenly now.
Bake: Bake uncovered for 22–28 minutes, or until the chicken reaches an internal temperature of 165°F (74°C). The top should be bubbly and lightly golden.
Broil for color (optional): If you want extra browning, broil on high for 1–2 minutes, watching closely.
Finish and rest: Let it rest for 5 minutes. Squeeze a little lime over the top if you like, and garnish with chopped cilantro or parsley.
Serve: Pair with a simple salad, steamed rice, cauliflower rice, or roasted broccoli.
Spoon any extra cheesy sauce from the pan over the sides.