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.

Form the mixture into evenly sized balls, approximately 4 cm in diameter, lightly dampening hands to prevent sticking.

Heat olive oil in a large skillet over medium heat until shimmering. Sear meatballs in batches 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.

Slice sub rolls lengthwise without cutting through completely. Place on a baking sheet and toast in the preheated oven for 5 minutes.

Arrange 4 to 5 meatballs inside each toasted roll and generously spoon additional BBQ sauce over the meatballs. Top with shredded cheddar cheese and crispy bacon.

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.