4 ounces, weight Shredded Provolone, Swiss Or Any Melting Cheese Of Your Choosing
Melt butter in a 6-quart stockpot over medium-high heat. Add onions, bay leaf and season with salt and pepper; stir to coat well. Saute until they begin to soften and become golden, about 15 minutes. Cover pot and reduce heat to medium-low. Cook, covered, until onions are softened, about 20 more minutes.
Remove and discard bay leaf. Stir, scraping up browned bits at the bottom of pot. Raise heat back to medium-high and slowly pour in the water. Add garlic clove, sherry vinegar and molasses. Bring to a boil. Reduce heat to a simmer and cook for 10 more minutes. Taste, and season with additional salt and pepper if necessary.
Preheat broiler. Evenly ladle soup into 4 oven-safe bowls. Place one slice of toasted baguette on top of each. Evenly sprinkle cheese on top and place on a rimmed baked sheet. Cook under the broiler until cheese is golden and bubbly, about 3 to 5 minutes.