Preheat oven to 375F degrees. Spray a 2-quart casserole dish with nonstick cooking spray.
Using an electric mixer (or a food processor), mix together the cream cheese, mayonnaise, Mexican blend cheese, ½ cup Parmesan cheese, green chiles and jalapeños. Add a pinch of salt and pepper.
Spread the dip filling into your casserole dish.
In a bowl, mix together Panko bread crumbs, 1/2 cup Parmesan cheese and melted butter (and a bit of dried parsley, optional).
Sprinkle crumb mixture evenly over dip filling.
Bake for about 20 minutes (on the middle rack).
Topping should be golden brown and the dip should be gently bubbling around the edges. Serve with your favorite buttery crackers or tortilla chips.