Preheat oven to 350 degrees. Lightly spray a 9 X 13-inch baking dish with nonstick cooking spray; set aside.
Prepare pasta, in well-salted water, according to package instructions. Drain pasta and transfer to another bowl; set aside.
Add butter to a large skillet and melt over medium heat. Whisk in flour, chili powder, cumin, and coriander then continue to cook, whisking constantly, for 1 minute or until spices become fragrant. Remove skillet from heat and slowly whisk in milk. Return to medium heat and cook, stirring constantly, until mixture thickens and begins to bubble.
Reduce heat to low and stir in well-drained Rotel, Worcestershire sauce, salt, pepper, American cheese, cream cheese and 1 1/2 cups sharp cheese. Cook until cheeses are melted. Stir in shredded chicken.
Add sauce to pasta pot and mix with spaghetti until noodles are all well coated in sauce. Pour into prepared baking dish.
For the topping, use a small skillet to melt butter. Add panko and oregano, allowing the bread crumbs to brown slightly. Once cooled, sprinkle panko over the top of spaghetti, then bake in preheated oven for 25-30 minutes. Before serving, sprinkle top with chopped cilantro and serve.