Heat oven to 375°F. Lightly grease a 9x13-inch baking dish.
Stir cream cheese, sour cream, and mayonnaise in a large bowl until smooth.
Season the mixture with garlic powder, onion powder, smoked paprika, salt, and pepper; mix well.
Fold in chicken, chopped jalapeños, half the bacon, and half of each cheese. Spread into the baking dish.
Top evenly with the remaining cheddar and Monterey Jack.
Toss panko with melted butter. Sprinkle the buttery crumbs over the casserole.
Bake until hot and bubbling with a golden top, 20–25 minutes. Broil 1 minute if you want extra color.
Rest 5 minutes. Scatter remaining bacon and green onions over the top, then serve warm.