Preheat oven to 400 degrees F. Wash and scrub sweet potatoes. Wrap in aluminum foil and bake for about 50 minutes to an hour or till soft all the way through when pierced with a knife. Remove from oven and allow to cool. When cool enough to handle, remove skins with a paper towel and discard.
Meanwhile, prepare rice by bringing 1-1/4 cups water to boil over HIGH heat. Add rice, stir, lower heat and cover pan. Simmer, covered, for about 20 minutes or until all water has been absorbed and rice is cooked. Remove pan from heat and set aside.
Place a large, heavy bottomed pot or Dutch oven over MEDIUM-LOW heat. Add lite coconut milk, chicken broth, and minced garlic. Allow mixture to get warm but do not allow to boil. Add about 3 cups of cooked sweet potato. Remove pot from heat and using an immersion blender, blend the sweet potato into the mixture in pan until smooth. Return pan to heat and add brown sugar, salt, curry powder, garam masala, and cayenne pepper. Add cooked rice and turn heat down to low. Allow soup to simmer for about 15 minutes. Soup will thicken as it simmers. Remove from heat when the soup is heated through and cooked to desired consistency.
Ladle into bowls and garnish individual servings with cilantro.
Reheats very well. If soup thickens too much in refrigerator, add a little water or additional chicken broth to thin out before reheating in microwave or on stove.