Cook and stir bacon in a large skillet over medium heat until bacon is translucent and beginning to brown, about 5 minutes; stir in onion and continue cooking and stirring until bacon is browned and sweet onion is translucent, about 5 more minutes.
Mix 1/2 cup ketchup, 2 tablespoons chili powder, 2 tablespoons ancho chile powder, 1 tablespoon Worcestershire sauce, cumin, salt, black pepper, and garlic powder in a large bowl.
Mix in ground sirloin, bacon-onion mixture, Cheddar cheese, pepper jack cheese, eggs, and bread crumbs until thoroughly combined. Form the mixture into a loaf shape and refrigerate 1 hour.
Preheat oven to 425 degrees F (220 degrees C). Line a 9x13-inch baking pan with aluminum foil and spray the foil with cooking spray.
Place loaf into the prepared baking dish.
Mix 1/2 cup ketchup, 1 tablespoon Worcestershire sauce, 1 teaspoon chili powder, and 1 teaspoon ground ancho chile in a bowl.
Spread the mixture over the loaf.
Bake in the preheated oven until the loaf is no longer pink inside and the juices run clear, 1 hour and 5 minutes to 1 hour and 15 minutes. An instant-read meat thermometer inserted into the center of the loaf should read at least 160 degrees F (70 degrees C).
