Preheat your oven to 375°F (190°C).

In a large bowl, combine the ground beef, bread crumbs, milk, egg, and ½ cup barbecue sauce.

Mix until well combined.

Form the mixture into meatballs, about 1 inch in diameter.

Place the meatballs on a baking sheet and bake for 20-25 minutes, or until fully cooked.

While the meatballs are cooking, prepare the sub rolls by slicing them open and toasting them lightly in the oven.

Once the meatballs are done, remove them from the oven and sprinkle them with the shredded cheddar cheese and chopped bacon.

Place the meatballs back in the oven and bake for an additional 5 minutes, or until the cheese is melted.

Remove the meatballs from the oven and assemble the subs by placing 3-4 meatballs on each roll.

Top each sub with additional barbecue sauce and cheddar cheese, if desired.

Serve immediately and enjoy your delicious BBQ Bacon Meatball Subs!