Preheat oven to 375°F (190°C). Grease a 9-inch square baking dish with cooking spray or softened butter.
Beat both blocks of softened cream cheese with a hand mixer or spatula until completely smooth with no visible lumps.
Add sour cream and mayonnaise. Mix until fully combined into one uniform base.
Fold in cheddar, Monterey Jack, diced jalapeños, drained green chiles, garlic, onion powder, smoked paprika, salt, and pepper until evenly distributed.
Spread the mixture evenly into the prepared baking dish.
In a small bowl, stir together panko, melted butter, Parmesan, garlic powder, and salt until all breadcrumbs are coated.
Scatter the panko topping evenly over the dip.
Bake on the center rack for 22 to 25 minutes, until the edges are actively bubbling and the topping is deep golden brown. Center of the dip should reach 74°C (165°F) on an instant-read thermometer.
Rest 5 minutes before serving.