Set the oven to 190°C to prepare for toasting the rolls.

In a large mixing bowl, combine ground beef, breadcrumbs, egg, garlic powder, onion powder, smoked paprika, salt, and pepper. Mix by hand just until evenly incorporated, taking care not to overwork the mixture.

Form the mixture into evenly sized balls approximately 4 cm in diameter. Lightly dampen hands to prevent sticking and roll gently for round, cohesive meatballs. Expect roughly 16 to 20 meatballs.

Heat olive oil in a large skillet over medium heat until shimmering. Arrange meatballs in a single layer, working in batches to avoid crowding. Sear each side until a deep brown crust forms, about 2 minutes per side.

Return all browned meatballs to the skillet. Pour bourbon BBQ sauce over them, reduce heat to low, and simmer gently for 10 minutes, occasionally basting the meatballs with sauce to ensure thorough coating and even cooking.

While meatballs simmer, slice sub rolls lengthwise without cutting through completely. Place on a baking sheet and toast in the preheated oven for 5 minutes until the exteriors are golden and crisp.

Arrange 4 to 5 meatballs inside each toasted roll. Generously spoon additional BBQ sauce over the meatballs. Top with 30 g shredded cheddar cheese and 2 slices of crispy bacon per roll, breaking bacon into pieces if preferred.

Return the filled subs to the oven for 2 to 3 minutes or until the cheese is thoroughly melted and bubbling.

Serve the subs immediately, accompanied by any remaining bourbon BBQ sauce for dipping.