Step 1: Cook the bacon in a skillet over medium heat until crispy, about 5-7 minutes. Let cool and crumble.

Step 2: In a mixing bowl, combine ground beef, crumbled bacon, panko breadcrumbs, and milk. Mix until well incorporated.

Step 3: In another bowl, whisk together egg, onion, garlic, Worcestershire sauce, Dijon mustard, smoked paprika, garlic powder, and onion powder.

Step 4: Combine wet mixture with meat mixture, adding salt and pepper. Mix gently.

Step 5: Flatten a portion of meat mixture, place a cheddar cube in the middle, encase and shape into a meatball.

Step 6: Preheat oven to 400°F (200°C). Arrange meatballs on a baking sheet and bake for 20-25 minutes.

Step 7: Alternatively, pan-fry meatballs in oil, cooking until browned and cooked through.

Step 8: Prepare burger sauce by mixing mayonnaise, ketchup, mustard, sweet relish, white vinegar, garlic powder, and smoked paprika.

Step 9: Serve meatballs on toasted buns with toppings or as appetizers with sauce.