Mollys Chicago Dog Meatloaf with Mustard Glaze

Name: Molly's Chicago Dog Meatloaf with Mustard Glaze
Ingredients: Nonstick cooking spray, for the pan; 1 tablespoon olive oil; 1 onion, finely chopped; 1/3 cup milk; Pinch poppy seeds; 3 stale hot dog buns, torn into pieces; 2 tablespoons sweet pickle relish; 1 teaspoon Worcestershire sauce; 1 teaspoon kosher salt; 1/2 teaspoon celery salt; 4 pickled sport peppers or pickled pepperoncini, finely chopped; 2 large eggs; 6 tablespoons yellow mustard; Freshly ground black pepper; 2 pounds ground beef (85% lean); 2 hot dogs; 2 tablespoons brown sugar; 2 tomatoes, sliced into wedges; 1 pickle, sliced into coins; Pinch of poppy seeds; Pinch of celery salt; 4 pickled sport peppers