Preheat the oven to 375 degrees F and lightly grease a loaf pan.
In a large bowl, combine the ground beef, breadcrumbs, egg, milk, onion, garlic, 2 tablespoons brown sugar, 2 tablespoons bourbon, salt, and black pepper. Mix until evenly blended but do not overwork the meat.
Press the mixture into the prepared loaf pan and smooth the top.
In a small bowl, stir together the remaining 1 tablespoon brown sugar, 1 tablespoon bourbon, smoked paprika, and ketchup until smooth.
Spread the glaze evenly over the top of the meatloaf.
Bake for 50 to 55 minutes, or until the internal temperature reaches 160 degrees F. Let the meatloaf rest for 5 minutes before slicing.