Heat the oil in a large pot over medium heat. Add the onions and sauté until softened, about 5 minutes. Add the garlic, ginger, coriander, and cinnamon and cook for another minute.
Add the vegetable broth, soy sauce, and brown sugar. Bring to a boil then reduce heat to low and simmer for 10 minutes.
Add the cooked vermicelli noodles and tofu cubes. Simmer for another 5 minutes.