Heat the oven to 375°F. Line a rimmed baking sheet with foil and set a wire rack on top.
In a large bowl, combine the egg, breadcrumbs, milk, diced onion, Worcestershire sauce, salt, and black pepper. Add the ground beef and mix gently until just combined.
Place half of the meat mixture on the rack and shape it into a small loaf. Make a shallow channel down the center, add the smoked cheddar cubes, then cover them with the remaining meat. Pinch the seams closed so the cheese is sealed inside.
Lay the bacon slices over the loaf, slightly overlapping them. Tuck the ends underneath to hold the bacon in place.
In a small bowl, stir together the brown sugar, bourbon, and ketchup. Brush half of the mixture over the bacon-wrapped loaf.
Bake until the center reaches 160°F, about 55 to 65 minutes. Brush with the remaining glaze during the last 15 minutes. Rest the meatloaf for 10 minutes before slicing so the cheese has time to settle.