In a bowl, combine 1/2 c. spaghetti sauce, egg, bread crumbs, and garlic.
Crumble meat over mixture and mix well.
Press two pieces of cheese, side by side, near one end of loaf. Cut the remaining piece of cheese in half, place side by side on opposite end of loaf.
Top with remaining meat mixture; press down firmly to seal.
Bake, uncovered, at 350 degrees for 1 1/4 - 1 1/2 hours or until meat is no longer pink and the internal temperature of the meat is 160 degrees, drain.
Drizzle with the remaining spaghetti sauce, bake 10 minutes longer. Let stand 10 minutes before serving.