Melt butter in a small pan over moderate heat. Add onions and garlic and season with sugar, and pepper. Cook 15 minutes, stirring occasionally, until onions are golden in color and translucent.
Place the split bread on a baking sheet and broil until golden. Spread half the onions and garlic on each half of bread in a thin layer. Sprinkle each side of loaf with a cup of Treasure Cave® Buffalo Wing Flavor Crumbled Blue Cheese and return to broiler for 30 seconds or until cheese bubbles.