Heat oil in a large Dutch oven or soup pot over medium heat. Add onions and cook until softened, about 2 to 3 minutes. Stir in garlic and chile peppers and continue cooking for 1 minute. Combine corn masa flour, bouillon powder and cumin in a small bowl. Stir to blend; add to pot with onions and mix well.
Gradually add water and mix well using a whisk. Add corn and bring to a boil. Reduce heat to low.
Ladle about ⅓ of the corn mixture into a blender or food processor. Add the half and half and puree for 30 seconds or until smooth. Pour pureed mixture back into the soup, stirring to combine.
Bring soup to a low boil; reduce heat and simmer for 10 minutes. Remove from heat and stir in cilantro. To serve, ladle into bowls and sprinkle with additional fresh cilantro and hot sauce, if desired.