Cook the ground bacon in a skillet over medium heat until crispy, about 8-10 minutes. Transfer to a paper towel-lined plate to drain and crumble.

In a large mixing bowl, gently combine ground beef, crumbled bacon, panko bread crumbs, and milk. Mix until just combined.

In a separate bowl, whisk together the beaten egg, diced onion, minced garlic, Worcestershire sauce, Dijon mustard, smoked paprika, garlic powder, and onion powder.

Pour the wet mixture into the bowl with the ground beef and bread crumbs. Season with salt and black pepper, and mix gently until fully combined.

Take a portion of the meat mixture, form it into a ball, flatten it slightly, place a cube of cheddar cheese in the center, then fold the meat around it.

Preheat oven to 400°F (200°C). Arrange meatballs on a lined baking sheet and bake for 20-25 minutes until they reach 160°F (71°C).

For pan-frying, heat oil in a skillet over medium heat, add meatballs and cook for 8-10 minutes, turning until browned, then cover and cook for an additional 5-7 minutes.

Prepare the burger sauce by combining mayonnaise, ketchup, yellow mustard, sweet pickle relish, white vinegar, garlic powder, paprika, and cayenne pepper.

To serve, place the cooked meatballs on toasted sesame seed buns and top with lettuce, tomato, red onion, and pickle chips.