Heat oil in a large pan over medium heat. Add onions, garlic, oregano, and cinnamon, then sauté for 5-7 minutes until onions are soft and translucent. Stir in chili powder and flour, then sauté for 3 minutes.
Gradually stir in broth and bring to a boil over medium-high heat. Reduce to medium-low and simmer for 30 minutes, stirring occasionally. Stir in dark cream, then season with salt and pepper. Set aside.
Preheat oven to 180 °C (350 °F). Rinse beans and corn in a colander and place in a large bowl. Dice avocado and tomato, slice spring onion, then add all to the bowl. Add garlic powder and coriander, mix well, and season with salt to taste.
Spread filling evenly over tortillas, then roll tightly with seam side down. Arrange seam-side down in a baking dish. Cover enchiladas with sauce, then bake at 180 °C (350 °F) for 25 minutes until heated through.