Heat canola oil in a large, heavy pot set over medium heat. Add onions and sauté until tender and light brown, about 10 minutes. Add cumin and oregano. Stir for 30 seconds, then add garlic cloves. Stir for an additional 30 seconds. Increase heat to medium-high. Add chili powder, bay leaves, cocoa powder, salt, and cinnamon. Chop tomatoes and add to the pot, along with the juices. Mix in tomato paste, chipotle peppers, adobo sauce, and vegetable broth. Bring to a boil, then reduce heat and simmer for 30 minutes, stirring occasionally. Remove and discard bay leaves.