Bake sweet potatoes the day before. Wash and dry the sweet potatoes cleaning any bad spots. With a fork or knife poke holes in the sweet potato then rub with butter and wrap in foil. Place the sweet potatoes in a baking dish. I like to line the dish with foil for easy cleanup. Bake in the oven at 400 degrees for 1 - 1 1/2 hours.
In a large pot, cook cut up bacon, chopped onions, and garlic on medium heat until crisp. Remove bacon, onion, and garlic and drain on a paper towel. Save it for a garnish on top of the soup. Keep bacon drippings in the pot for later.
Take sweet potatoes from the refrigerator. Peel skins off. Place in bowl and mash.
In the same pot with the bacon drippings add mashed sweet potatoes, and two tablespoons of butter.
Add a container of chicken broth, bay leaves, and salt. Stir till well mixed.
Simmer on low heat for 2 hours.
Remove bay leaves.
Puree mixture with an emersion blender, or in batches with a regular blender.
Add whipping cream. Blend well.
Garnish with bacon topping, sage or other herb if desired.