Preheat the oven to 350°F and lightly grease a 13 x 9-inch baking dish with cooking spray to prevent sticking.
In a large microwave-safe bowl, heat the cream cheese and sour cream on HIGH for approximately 1 minute and 30 seconds, or until the cream cheese becomes soft. Whisk together until the mixture is smooth and fully combined.
Add the refried beans, chopped green chiles, taco seasoning, salt, smoked paprika, chili powder, onion powder, and cayenne pepper to the cream cheese mixture. Stir well to ensure the spices and ingredients are evenly distributed. Fold in 2 cups of the shredded Mexican cheese blend, mixing until the dip is creamy and uniform.
Spread the mixture evenly into the prepared baking dish, smoothing out the top. Sprinkle the remaining 2 cups of shredded cheese over the surface, covering it completely for a gooey, golden topping.
Bake for about 25 minutes, or until the cheese is fully melted and bubbling around the edges. Once out of the oven, garnish with sliced scallions for a pop of color and freshness. Serve warm with crispy tortilla chips for dipping.