Heat oven to 375°F. Lightly grease a 9×13-inch baking dish.
Pat chicken breasts dry with paper towels. Season both sides with salt and pepper. Sprinkle HALF of the ranch seasoning packet evenly over the chicken. Lay them flat in the prepared baking dish.
In a medium bowl, combine softened cream cheese, the remaining HALF of the ranch seasoning, diced jalapeños, and green chiles. Stir until smooth.
Spread the cream cheese mixture evenly over the chicken breasts. Top with Colby Jack and pepper jack cheese. If using bacon, sprinkle crumbles over the top.
Bake uncovered for 30–35 minutes, or until chicken is cooked through (internal temp 165°F) and cheese is golden and melty.
For extra color and crispness, broil the top for 2–3 minutes at the end.
Top with sliced jalapeños or fresh parsley. Serve hot with rice, roasted veggies, or a crisp salad.